diff --git a/storm-core/src/main/java/st/orm/core/repository/impl/EntityRepositoryImpl.java b/storm-core/src/main/java/st/orm/core/repository/impl/EntityRepositoryImpl.java
index ea105f4ad..53f3546a3 100644
--- a/storm-core/src/main/java/st/orm/core/repository/impl/EntityRepositoryImpl.java
+++ b/storm-core/src/main/java/st/orm/core/repository/impl/EntityRepositoryImpl.java
@@ -30,6 +30,7 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -1717,16 +1718,7 @@ protected void insert(List<E> batch, PreparedQuery query, boolean ignoreAutoGene
         if (batch.isEmpty()) {
             return;
         }
-        List<E> transformed = batch.stream()
-                .map(this::fireBeforeInsert)
-                .toList();
-        transformed.stream()
-                .map(e -> validateInsert(e, ignoreAutoGenerate))
-                .forEach(query::addBatch);
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 1)) {
-            throw new PersistenceException("Batch insert of %s failed. One or more rows were not affected.".formatted(model.type().getSimpleName()));
-        }
+        List<E> transformed = executeInsertBatch(batch, query, ignoreAutoGenerate);
         transformed.forEach(this::fireAfterInsert);
     }
 
@@ -1739,16 +1731,7 @@ private List<ID> insertAndFetchIds(List<E> batch, PreparedQuery query, boolean i
         if (batch.isEmpty()) {
             return List.of();
         }
-        List<E> transformed = batch.stream()
-                .map(this::fireBeforeInsert)
-                .toList();
-        transformed.stream()
-                .map(e -> validateInsert(e, ignoreAutoGenerate))
-                .forEach(query::addBatch);
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 1)) {
-            throw new PersistenceException("Batch insert of %s failed. One or more rows were not affected.".formatted(model.type().getSimpleName()));
-        }
+        List<E> transformed = executeInsertBatch(batch, query, ignoreAutoGenerate);
         List<ID> ids;
         if (isAutoGeneratedPrimaryKey() && !ignoreAutoGenerate) {
             try (var stream = query.getGeneratedKeys(model.primaryKeyType())) {
@@ -1761,6 +1744,26 @@ private List<ID> insertAndFetchIds(List<E> batch, PreparedQuery query, boolean i
         return ids;
     }
 
+    /**
+     * Runs the batch through the prepared insert: fires the before-insert callbacks, validates, executes the
+     * batch and checks that every row was inserted.
+     *
+     * @return the entities as transformed by the before-insert callbacks.
+     */
+    private List<E> executeInsertBatch(List<E> batch, PreparedQuery query, boolean ignoreAutoGenerate) {
+        List<E> transformed = batch.stream()
+                .map(this::fireBeforeInsert)
+                .toList();
+        transformed.stream()
+                .map(e -> validateInsert(e, ignoreAutoGenerate))
+                .forEach(query::addBatch);
+        int[] result = query.executeBatch();
+        if (IntStream.of(result).anyMatch(r -> r != 1)) {
+            throw new PersistenceException("Batch insert of %s failed. One or more rows were not affected.".formatted(model.type().getSimpleName()));
+        }
+        return transformed;
+    }
+
     /**
      * Updates a stream of entities in the database using the default batch size.
      *
@@ -1984,22 +1987,7 @@ protected PreparedQuery prepareUpdateQuery(Set<Metamodel<?, ?>> fields) {
     }
 
     protected void update(List<E> batch, PreparedQuery query, @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return;
-        }
-        batch.stream().map(this::validateUpdate).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (query.isVersionAware() && IntStream.of(result).anyMatch(r -> r == 0)) {
-            throw new OptimisticLockException("Batch update of %s failed due to optimistic lock. One or more entities may have been modified or deleted by another transaction.".formatted(model.type().getSimpleName()));
-        } else if (IntStream.of(result).anyMatch(r -> r != 1)) {
-            throw new PersistenceException("Batch update of %s failed. One or more rows were not affected.".formatted(model.type().getSimpleName()));
-        }
-        batch.forEach(this::fireAfterUpdate);
+        updateAndFetchIds(batch, query, cache);
     }
 
     protected List<ID> updateAndFetchIds(List<E> batch, PreparedQuery query, @Nullable EntityCache<E, ID> cache) {
@@ -2168,6 +2156,124 @@ protected List<ID> doUpsertAndFetchIdsBatch(List<E> batch, PreparedQuery query,
         throw upsertNotAvailable();
     }
 
+    // Partition keys for the dialects' id-returning upsertAndFetchIds implementations.
+    public sealed interface SeqPartitionKey {}
+    public static final class SeqNoOpKey implements SeqPartitionKey {
+        public static final SeqNoOpKey INSTANCE = new SeqNoOpKey();
+        private SeqNoOpKey() {
+        }
+    }
+    public static final class SeqUpsertKey implements SeqPartitionKey {
+        public static final SeqUpsertKey INSTANCE = new SeqUpsertKey();
+        private SeqUpsertKey() {
+        }
+    }
+    public record SeqUpdateKey(Set<Metamodel<?, ?>> fields) implements SeqPartitionKey {
+        public SeqUpdateKey() {
+            this(Set.of()); // All fields.
+        }
+    }
+
+    /**
+     * The upsert-and-fetch-ids loop for dialects that fetch the ids through a single id-returning query
+     * (such as {@code INSERT ... RETURNING} or {@code MERGE ... OUTPUT}) rather than batched prepared
+     * statements: the entities are partitioned into no-op, upsert and per-shape update batches, and the
+     * resulting ids come back in entity order.
+     *
+     * @param entities the entities to upsert.
+     * @param upsertPartition executes one upsert partition and returns its ids; receives the partition's
+     *                        chunk and the entity cache in effect for the operation. Dialects with the
+     *                        standard cache-eviction semantics pass {@link #upsertPartitionAndFetchIds}.
+     * @return the ids of the upserted entities.
+     * @since 1.14
+     */
+    protected List<ID> upsertAndFetchIdsPartitioned(
+            Iterable<E> entities,
+            BiFunction<List<E>, Optional<EntityCache<E, ID>>, List<ID>> upsertPartition) {
+        var updateQueries = new HashMap<Set<Metamodel<?, ?>>, PreparedQuery>();
+        try {
+            var result = new ArrayList<ID>();
+            var entityCache = entityCache();
+            partitioned(toStream(entities), defaultBatchSize, entity -> {
+                if (isUpsertUpdate(entity)) {
+                    var dirty = getDirty(entity, entityCache.orElse(null));
+                    if (dirty.isEmpty()) {
+                        return SeqNoOpKey.INSTANCE;
+                    }
+                    return new SeqUpdateKey(dirty.get());
+                } else {
+                    return SeqUpsertKey.INSTANCE;
+                }
+            }, getMaxShapes(), new SeqUpdateKey()).forEach(partition -> {
+                switch (partition.key()) {
+                    case SeqNoOpKey ignore -> result.addAll(partition.chunk().stream().map(E::id).toList());
+                    case SeqUpsertKey ignore -> result.addAll(upsertPartition.apply(partition.chunk(), entityCache));
+                    case SeqUpdateKey u -> {
+                        List<E> batch = hasEntityCallbacks()
+                                ? partition.chunk().stream().map(this::fireBeforeUpdate).toList()
+                                : partition.chunk();
+                        result.addAll(updateAndFetchIds(batch,
+                                updateQueries.computeIfAbsent(u.fields(), this::prepareUpdateQuery),
+                                entityCache.orElse(null)));
+                    }
+                }
+            });
+            return result;
+        } finally {
+            closeQuietly(updateQueries.values().stream());
+        }
+    }
+
+    /**
+     * Executes one upsert partition through a single id-returning query: fires the before-upsert callbacks,
+     * evicts the entities with non-default primary keys from the cache (the upsert may update them), runs
+     * the query and reports the returned ids to the after-upsert callbacks.
+     *
+     * @param chunk the partition's entities.
+     * @param entityCache the entity cache in effect for the operation.
+     * @param upsertQuery creates the id-returning upsert query for a batch.
+     * @return the ids of the upserted entities.
+     * @since 1.14
+     */
+    protected List<ID> upsertPartitionAndFetchIds(List<E> chunk,
+                                                  Optional<EntityCache<E, ID>> entityCache,
+                                                  Function<List<E>, Query> upsertQuery) {
+        List<E> batch = hasEntityCallbacks()
+                ? chunk.stream().map(this::fireBeforeUpsert).toList()
+                : chunk;
+        entityCache.ifPresent(cache -> batch.stream()
+                .filter(e -> !model.isDefaultPrimaryKey(e.id()))
+                .forEach(e -> cache.remove(e.id())));
+        List<ID> ids = upsertQuery.apply(batch).getResultList(model.primaryKeyType());
+        fireAfterUpsert(batch, ids);
+        return ids;
+    }
+
+    /**
+     * Inserts the entity and fetches the generated primary key through the dialect's
+     * {@code INSERT ... RETURNING} clause, for dialects whose driver cannot report sequence-generated
+     * keys through {@code getGeneratedKeys()}.
+     *
+     * @param entity the entity to insert.
+     * @return the primary key of the inserted entity.
+     * @since 1.14
+     */
+    protected ID insertAndFetchIdReturning(E entity) {
+        entity = fireBeforeInsert(entity);
+        validateInsert(entity);
+        assert primaryKeyColumns.size() == 1;
+        var primaryKeyColumn = primaryKeyColumns.getFirst();
+        String pkName = primaryKeyColumn.qualifiedName(ormTemplate.dialect());
+        try (var query = ormTemplate.query(TemplateString.raw("""
+                INSERT INTO \0
+                VALUES \0
+                RETURNING %s""".formatted(pkName), model.type(), entity)).managed().prepare()) {
+            ID id = query.getSingleResult(model.primaryKeyType());
+            fireAfterInsert(entity, id);
+            return id;
+        }
+    }
+
     /**
      * Removes a stream of entities from the database in batches.
      *
diff --git a/storm-core/src/main/java/st/orm/core/repository/impl/MergeEntityRepositoryImpl.java b/storm-core/src/main/java/st/orm/core/repository/impl/MergeEntityRepositoryImpl.java
index f975cea6a..5934a45f4 100644
--- a/storm-core/src/main/java/st/orm/core/repository/impl/MergeEntityRepositoryImpl.java
+++ b/storm-core/src/main/java/st/orm/core/repository/impl/MergeEntityRepositoryImpl.java
@@ -278,17 +278,7 @@ private TemplateString mergeStatement(TemplateString mergeSelect, AtomicBoolean
      */
     @Override
     protected void doUpsert(E entity) {
-        validateUpsert(entity);
-        entityCache().ifPresent(cache -> {
-            if (!model.isDefaultPrimaryKey(entity.id())) {
-                cache.remove(entity.id());
-            }
-        });
-        var versionAware = new AtomicBoolean();
-        intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
-            var query = ormTemplate.query(mergeStatement(mergeSelect(entity), versionAware)).managed();
-            query.executeUpdate();
-        });
+        doUpsertAndFetchId(entity);
     }
 
     /**
@@ -322,19 +312,7 @@ protected PreparedQuery prepareUpsertQuery() {
     @Override
     protected void doUpsertBatch(List<E> batch, PreparedQuery query,
                                  @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return;
-        }
-        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
-            throw new PersistenceException(upsertFailureMessage(batch.size()));
-        }
+        doUpsertAndFetchIdsBatch(batch, query, cache);
     }
 
     @Override
diff --git a/storm-core/src/main/java/st/orm/core/repository/impl/OnConflictEntityRepositoryImpl.java b/storm-core/src/main/java/st/orm/core/repository/impl/OnConflictEntityRepositoryImpl.java
new file mode 100644
index 000000000..16c72fe53
--- /dev/null
+++ b/storm-core/src/main/java/st/orm/core/repository/impl/OnConflictEntityRepositoryImpl.java
@@ -0,0 +1,214 @@
+/*
+ * Copyright 2024 - 2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package st.orm.core.repository.impl;
+
+import static java.util.function.Predicate.not;
+import static st.orm.core.template.SqlInterceptor.intercept;
+import static st.orm.core.template.TemplateString.combine;
+import static st.orm.core.template.TemplateString.raw;
+import static st.orm.core.template.Templates.table;
+import static st.orm.core.template.impl.StringTemplates.flatten;
+
+import java.math.BigInteger;
+import java.sql.Timestamp;
+import java.time.Instant;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.stream.IntStream;
+import org.jspecify.annotations.Nullable;
+import st.orm.Data;
+import st.orm.Entity;
+import st.orm.NoResultException;
+import st.orm.NonUniqueResultException;
+import st.orm.PersistenceException;
+import st.orm.core.repository.EntityRepository;
+import st.orm.core.spi.EntityCache;
+import st.orm.core.template.Column;
+import st.orm.core.template.Model;
+import st.orm.core.template.ORMTemplate;
+import st.orm.core.template.PreparedQuery;
+import st.orm.core.template.TemplateString;
+
+/**
+ * Implementation of {@link EntityRepository} for dialects that upsert through the
+ * {@code INSERT ... ON CONFLICT (<primary_keys>) DO UPDATE SET ...} clause with the {@code EXCLUDED}
+ * pseudo-table, such as PostgreSQL and SQLite.
+ *
+ * @since 1.14
+ */
+public class OnConflictEntityRepositoryImpl<E extends Entity<ID>, ID>
+        extends EntityRepositoryImpl<E, ID> {
+
+    protected OnConflictEntityRepositoryImpl(ORMTemplate ormTemplate, Model<E, ID> model) {
+        super(ormTemplate, model);
+    }
+
+    private TemplateString getVersionString(Class<? extends Data> type, Column column) {
+        TemplateString columnName = TemplateString.of(column.qualifiedName(ormTemplate.dialect()));
+        TemplateString updateExpression = switch (column.type()) {
+            case Class<?> c when Integer.TYPE.isAssignableFrom(c)
+                    || Long.TYPE.isAssignableFrom(c)
+                    || Integer.class.isAssignableFrom(c)
+                    || Long.class.isAssignableFrom(c)
+                    || BigInteger.class.isAssignableFrom(c) -> raw("\0.\0 + 1", table(type), columnName);
+            case Class<?> c when Instant.class.isAssignableFrom(c)
+                    || Date.class.isAssignableFrom(c)
+                    || Calendar.class.isAssignableFrom(c)
+                    || Timestamp.class.isAssignableFrom(c) -> TemplateString.of(ormTemplate.dialect().currentTimestamp());
+            default ->
+                    throw new PersistenceException("Unsupported version type: %s.".formatted(column.type().getSimpleName()));
+        };
+        return flatten(raw("\0 = \0", columnName, updateExpression));
+    }
+
+    /**
+     * Constructs the conflict clause for an upsert.
+     *
+     * <p>This method builds an "ON CONFLICT (&lt;primary_keys&gt;) DO UPDATE SET ..." clause.
+     * For non-primary key columns, it assigns the value from the EXCLUDED pseudo-table.
+     * Version columns are updated using {@link #getVersionString(Class, Column)}.</p>
+     *
+     * @param versionAware a flag that will be set if a version column is encountered.
+     * @return the conflict clause as a TemplateString.
+     */
+    protected TemplateString onConflictClause(AtomicBoolean versionAware) {
+        var dialect = ormTemplate.dialect();
+        // Determine the conflict target from primary key columns.
+        String conflictTarget = model.declaredColumns().stream()
+                .filter(Column::primaryKey)
+                .map(c -> c.qualifiedName(dialect))
+                .reduce("%s, %s"::formatted)
+                .orElseThrow(() -> new PersistenceException("No primary key defined."));
+        // Build the assignment list for non-primary key updatable columns.
+        var assignments = model.declaredColumns().stream()
+                .filter(not(Column::primaryKey))
+                .filter(Column::updatable)
+                .map(column -> {
+                    if (column.version()) {
+                        versionAware.setPlain(true);
+                        return getVersionString(model.type(), column);
+                    }
+                    return TemplateString.of("%s = EXCLUDED.%s".formatted(column.qualifiedName(dialect), column.qualifiedName(dialect)));
+                })
+                .reduce((left, right) -> combine(left, TemplateString.of(", "), right))
+                .map(st -> combine(TemplateString.of("DO UPDATE SET "), st))
+                .orElse(TemplateString.of("DO NOTHING"));
+        return flatten(combine(TemplateString.of("\nON CONFLICT ("), TemplateString.of(conflictTarget), raw(") \0", assignments)));
+    }
+
+    @Override
+    protected void doUpsert(E entity) {
+        validateUpsert(entity);
+        entityCache().ifPresent(cache -> {
+            if (!model.isDefaultPrimaryKey(entity.id())) {
+                cache.remove(entity.id());
+            }
+        });
+        var versionAware = new AtomicBoolean();
+        intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
+            var query = ormTemplate.query(flatten(raw("""
+                    INSERT INTO \0
+                    VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed();
+            query.executeUpdate();
+        });
+    }
+
+    /**
+     * Performs the upsert and reads the primary key back through the driver's generated keys. Dialects with
+     * an id-returning path for sequence-generated keys override this method and fall back to this
+     * implementation for the other generation strategies.
+     */
+    @Override
+    protected ID doUpsertAndFetchId(E entity) {
+        validateUpsert(entity);
+        entityCache().ifPresent(cache -> {
+            if (!model.isDefaultPrimaryKey(entity.id())) {
+                cache.remove(entity.id());
+            }
+        });
+        var versionAware = new AtomicBoolean();
+        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
+            try (var query = ormTemplate.query(flatten(raw("""
+                        INSERT INTO \0
+                        VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed().prepare()) {
+                query.executeUpdate();
+                if (isAutoGeneratedPrimaryKey()) {
+                    try (var stream = query.getGeneratedKeys(model.primaryKeyType())) {
+                        return stream.reduce((ignore1, ignore2) -> {
+                            throw new NonUniqueResultException("Expected single result, but found more than one.");
+                        }).orElseThrow(() -> new NoResultException("Expected single result, but found none."));
+                    }
+                }
+                return entity.id();
+            }
+        });
+    }
+
+    @Override
+    protected PreparedQuery prepareUpsertQuery() {
+        var bindVars = ormTemplate.createBindVars();
+        var versionAware = new AtomicBoolean();
+        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () ->
+                ormTemplate.query(flatten(raw("""
+                    INSERT INTO \0
+                    VALUES \0\0""", model.type(), bindVars, onConflictClause(versionAware))))
+                        .managed().prepare());
+    }
+
+    @Override
+    protected void doUpsertBatch(List<E> batch, PreparedQuery query,
+                                 @Nullable EntityCache<E, ID> cache) {
+        if (batch.isEmpty()) {
+            return;
+        }
+        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
+        if (cache != null) {
+            batch.stream()
+                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
+                    .forEach(e -> cache.remove(e.id()));
+        }
+        int[] result = query.executeBatch();
+        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
+            throw new PersistenceException(upsertFailureMessage(batch.size()));
+        }
+    }
+
+    @Override
+    protected List<ID> doUpsertAndFetchIdsBatch(List<E> batch, PreparedQuery query,
+                                                @Nullable EntityCache<E, ID> cache) {
+        if (batch.isEmpty()) {
+            return List.of();
+        }
+        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
+        if (cache != null) {
+            batch.stream()
+                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
+                    .forEach(e -> cache.remove(e.id()));
+        }
+        int[] result = query.executeBatch();
+        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
+            throw new PersistenceException(upsertFailureMessage(batch.size()));
+        }
+        if (isAutoGeneratedPrimaryKey()) {
+            try (var generatedKeys = query.getGeneratedKeys(model.primaryKeyType())) {
+                return generatedKeys.toList();
+            }
+        }
+        return batch.stream().map(Entity::id).toList();
+    }
+}
diff --git a/storm-core/src/main/java/st/orm/core/spi/AbstractRef.java b/storm-core/src/main/java/st/orm/core/spi/AbstractRef.java
index 5174b0e96..8fd2e93ee 100644
--- a/storm-core/src/main/java/st/orm/core/spi/AbstractRef.java
+++ b/storm-core/src/main/java/st/orm/core/spi/AbstractRef.java
@@ -18,6 +18,7 @@
 import java.util.Objects;
 import st.orm.Data;
 import st.orm.Ref;
+import st.orm.core.template.impl.LazySupplier;
 
 /**
  * Abstract implementation of {@link Ref} to have consistent implementations of {@link #hashCode()}
@@ -30,9 +31,14 @@
  * as-is.</p>
  *
  * @param <T> record type.
+ * @param <ID> primary key type.
  * @since 1.3
  */
-abstract class AbstractRef<T extends Data> implements Ref<T> {
+abstract class AbstractRef<T extends Data, ID> extends BaseRef<T, ID> {
+
+    AbstractRef(LazySupplier<T> supplier, Class<T> type, ID pk) {
+        super(supplier, type, pk);
+    }
 
     /**
      * Lazily computed row identity of the id. Computed outside construction because only map-keyed usage needs the
@@ -72,7 +78,7 @@ public boolean equals(Object obj) {
         if (this == obj) {
             return true;
         }
-        if (obj instanceof AbstractRef<?> other) {
+        if (obj instanceof AbstractRef<?, ?> other) {
             return Objects.equals(type(), other.type())
                     && Objects.equals(rowId(), other.rowId());
         }
diff --git a/storm-core/src/main/java/st/orm/core/spi/BaseRef.java b/storm-core/src/main/java/st/orm/core/spi/BaseRef.java
new file mode 100644
index 000000000..3da7b75a8
--- /dev/null
+++ b/storm-core/src/main/java/st/orm/core/spi/BaseRef.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2024 - 2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package st.orm.core.spi;
+
+import static java.util.Objects.requireNonNull;
+
+import org.jspecify.annotations.Nullable;
+import st.orm.Data;
+import st.orm.Entity;
+import st.orm.Ref;
+import st.orm.core.repository.EntityRepository;
+import st.orm.core.template.impl.LazySupplier;
+
+/**
+ * Base implementation for the attached {@link Ref} implementations: holds the record type, the primary key and
+ * the lazy supplier the record is fetched through. Identity semantics are left to the subclasses, which differ
+ * in whether they cache a normalized row identity.
+ *
+ * @param <T> record type.
+ * @param <ID> primary key type.
+ * @since 1.14
+ */
+abstract class BaseRef<T extends Data, ID> implements Ref<T> {
+    private final LazySupplier<T> supplier;
+    private final Class<T> type;
+    private final ID pk;
+
+    BaseRef(LazySupplier<T> supplier, Class<T> type, ID pk) {
+        this.supplier = requireNonNull(supplier, "supplier");
+        this.type = requireNonNull(type, "type");
+        this.pk = requireNonNull(pk, "pk");
+    }
+
+    /**
+     * The type of the record.
+     *
+     * @return the type of the record.
+     */
+    @Override
+    public Class<T> type() {
+        return type;
+    }
+
+    /**
+     * Returns the record if it has already been fetched, without triggering a database call.
+     *
+     * @return the record if already loaded, or {@code null} if not yet fetched.
+     * @since 1.7
+     */
+    @Nullable
+    @Override
+    public T getOrNull() {
+        return supplier.value().orElse(null);
+    }
+
+    /**
+     * Returns the primary key of the record.
+     *
+     * <p>This method is provided for convenience. If the type of the id is known, you can cast it to the appropriate
+     * type.</p>
+     *
+     * @return the primary key as an Object.
+     */
+    @Override
+    public ID id() {
+        return pk;
+    }
+
+    /**
+     * Fetches the record from the database if the record has not been fetched yet. The record will be fetched at most
+     * once.
+     *
+     * @return the fetched record.
+     * @since 1.7
+     */
+    @Override
+    public T fetchOrNull() {
+        return supplier.get();
+    }
+
+    /**
+     * Returns whether this ref is attached to a database context and capable of fetching the record on demand.
+     *
+     * <p>A fetchable ref has access to a database connection and can attempt to retrieve the record when
+     * {@link #fetch()} or {@link #fetchOrNull()} is called. A non-fetchable (detached) ref can only return
+     * data that was already loaded at the time of its creation.</p>
+     *
+     * <p>Note that this method indicates the <em>capability</em> to fetch, not a guarantee of success. A fetchable
+     * ref may still fail to retrieve a record if it has been deleted from the database or if the connection
+     * encounters an error.</p>
+     *
+     * @return {@code true} if this ref can attempt to fetch from the database, {@code false} if it is detached.
+     * @since 1.7
+     */
+    @Override
+    public boolean isFetchable() {
+        return true;
+    }
+
+    /**
+     * Returns a detached ref with the same identity but without data. The returned ref is not attached to a database
+     * context. To obtain an attached ref that can re-fetch the record, use
+     * {@link EntityRepository#unload(Entity) EntityRepository.unload()} instead.
+     *
+     * @return a detached ref with the same type and primary key but without cached data.
+     */
+    @Override
+    public Ref<T> unload() {
+        return Ref.of(type, pk);
+    }
+}
diff --git a/storm-core/src/main/java/st/orm/core/spi/Providers.java b/storm-core/src/main/java/st/orm/core/spi/Providers.java
index e6314037f..315f89f0a 100644
--- a/storm-core/src/main/java/st/orm/core/spi/Providers.java
+++ b/storm-core/src/main/java/st/orm/core/spi/Providers.java
@@ -311,7 +311,7 @@ public static String getDatabaseProductName(DataSource dataSource) {
         }
         return DATABASE_PRODUCT_NAMES.computeIfAbsent(new DataSourceIdentity(dataSource, DATA_SOURCE_QUEUE), ignore -> {
             try (Connection connection = dataSource.getConnection()) {
-                return connection.getMetaData().getDatabaseProductName();
+                return getDatabaseProductName(connection);
             } catch (SQLException e) {
                 throw new PersistenceException("Failed to determine database product name.", e);
             }
@@ -358,12 +358,7 @@ public static String getDatabaseProductName(Connection connection) {
      * @since 1.11
      */
     public static SqlDialect getSqlDialect(DataSource dataSource, StormConfig config) {
-        String productName = getDatabaseProductName(dataSource);
-        return enabled(SQL_DIALECT_PROVIDERS)
-                .filter(p -> p.supports(productName))
-                .map(p -> p.getSqlDialect(config))
-                .findFirst()
-                .orElseThrow();
+        return sqlDialectFor(getDatabaseProductName(dataSource), config);
     }
 
     /**
@@ -376,7 +371,10 @@ public static SqlDialect getSqlDialect(DataSource dataSource, StormConfig config
      * @since 1.11
      */
     public static SqlDialect getSqlDialect(Connection connection, StormConfig config) {
-        String productName = getDatabaseProductName(connection);
+        return sqlDialectFor(getDatabaseProductName(connection), config);
+    }
+
+    private static SqlDialect sqlDialectFor(String productName, StormConfig config) {
         return enabled(SQL_DIALECT_PROVIDERS)
                 .filter(p -> p.supports(productName))
                 .map(p -> p.getSqlDialect(config))
diff --git a/storm-core/src/main/java/st/orm/core/spi/RefImpl.java b/storm-core/src/main/java/st/orm/core/spi/RefImpl.java
index ec520a1bf..2bdb65894 100644
--- a/storm-core/src/main/java/st/orm/core/spi/RefImpl.java
+++ b/storm-core/src/main/java/st/orm/core/spi/RefImpl.java
@@ -15,13 +15,8 @@
  */
 package st.orm.core.spi;
 
-import static java.util.Objects.requireNonNull;
-
-import org.jspecify.annotations.Nullable;
 import st.orm.Data;
-import st.orm.Entity;
 import st.orm.Ref;
-import st.orm.core.repository.EntityRepository;
 import st.orm.core.template.impl.LazySupplier;
 
 /**
@@ -30,92 +25,9 @@
  * @param <T> record type.
  * @param <ID> primary key type.
  */
-final class RefImpl<T extends Data, ID> extends AbstractRef<T> {
-    private final LazySupplier<T> supplier;
-    private final Class<T> type;
-    private final ID pk;
+final class RefImpl<T extends Data, ID> extends AbstractRef<T, ID> {
 
     RefImpl(LazySupplier<T> supplier, Class<T> type, ID pk) {
-        this.supplier = requireNonNull(supplier, "supplier");
-        this.type = requireNonNull(type, "type");
-        this.pk = requireNonNull(pk, "pk");
-    }
-
-    /**
-     * The type of the record.
-     *
-     * @return the type of the record.
-     */
-    @Override
-    public Class<T> type() {
-        return type;
-    }
-
-    /**
-     * Returns the record if it has already been fetched, without triggering a database call.
-     *
-     * @return the record if already loaded, or {@code null} if not yet fetched.
-     * @since 1.7
-     */
-    @Nullable
-    @Override
-    public T getOrNull() {
-        return supplier.value().orElse(null);
-    }
-
-    /**
-     * Returns the primary key of the record.
-     *
-     * <p>This method is provided for convenience. If the type of the id is known, you can cast it to the appropriate
-     * type.</p>
-     *
-     * @return the primary key as an Object.
-     */
-    @Override
-    public ID id() {
-        return pk;
-    }
-
-    /**
-     * Fetches the record from the database if the record has not been fetched yet. The record will be fetched at most
-     * once.
-     *
-     * @return the fetched record.
-     * @since 1.7
-     */
-    @Override
-    public T fetchOrNull() {
-        return supplier.get();
-    }
-
-    /**
-     * Returns whether this ref is attached to a database context and capable of fetching the record on demand.
-     *
-     * <p>A fetchable ref has access to a database connection and can attempt to retrieve the record when
-     * {@link #fetch()} or {@link #fetchOrNull()} is called. A non-fetchable (detached) ref can only return
-     * data that was already loaded at the time of its creation.</p>
-     *
-     * <p>Note that this method indicates the <em>capability</em> to fetch, not a guarantee of success. A fetchable
-     * ref may still fail to retrieve a record if it has been deleted from the database or if the connection
-     * encounters an error.</p>
-     *
-     * @return {@code true} if this ref can attempt to fetch from the database, {@code false} if it is detached.
-     * @since 1.7
-     */
-    @Override
-    public boolean isFetchable() {
-        return true;
-    }
-
-    /**
-     * Returns a detached ref with the same identity but without data. The returned ref is not attached to a database
-     * context. To obtain an attached ref that can re-fetch the record, use
-     * {@link EntityRepository#unload(Entity) EntityRepository.unload()} instead.
-     *
-     * @return a detached ref with the same type and primary key but without cached data.
-     */
-    @Override
-    public Ref<T> unload() {
-        return Ref.of(type, pk);
+        super(supplier, type, pk);
     }
 }
diff --git a/storm-core/src/main/java/st/orm/core/spi/ScalarRefImpl.java b/storm-core/src/main/java/st/orm/core/spi/ScalarRefImpl.java
index bd8fd7d33..fc9c3836f 100644
--- a/storm-core/src/main/java/st/orm/core/spi/ScalarRefImpl.java
+++ b/storm-core/src/main/java/st/orm/core/spi/ScalarRefImpl.java
@@ -15,14 +15,9 @@
  */
 package st.orm.core.spi;
 
-import static java.util.Objects.requireNonNull;
-
 import java.util.Objects;
-import org.jspecify.annotations.Nullable;
 import st.orm.Data;
-import st.orm.Entity;
 import st.orm.Ref;
-import st.orm.core.repository.EntityRepository;
 import st.orm.core.template.impl.LazySupplier;
 
 /**
@@ -38,84 +33,15 @@
  * @param <T> record type.
  * @param <ID> primary key type.
  */
-final class ScalarRefImpl<T extends Data, ID> implements Ref<T> {
-    private final LazySupplier<T> supplier;
-    private final Class<T> type;
-    private final ID pk;
+final class ScalarRefImpl<T extends Data, ID> extends BaseRef<T, ID> {
 
     ScalarRefImpl(LazySupplier<T> supplier, Class<T> type, ID pk) {
-        this.supplier = requireNonNull(supplier, "supplier");
-        this.type = requireNonNull(type, "type");
-        this.pk = requireNonNull(pk, "pk");
-    }
-
-    /**
-     * The type of the record.
-     *
-     * @return the type of the record.
-     */
-    @Override
-    public Class<T> type() {
-        return type;
-    }
-
-    /**
-     * Returns the record if it has already been fetched, without triggering a database call.
-     *
-     * @return the record if already loaded, or {@code null} if not yet fetched.
-     */
-    @Nullable
-    @Override
-    public T getOrNull() {
-        return supplier.value().orElse(null);
-    }
-
-    /**
-     * Returns the primary key of the record.
-     *
-     * @return the primary key as an Object.
-     */
-    @Override
-    public ID id() {
-        return pk;
-    }
-
-    /**
-     * Fetches the record from the database if the record has not been fetched yet. The record will be fetched at
-     * most once.
-     *
-     * @return the fetched record.
-     */
-    @Override
-    public T fetchOrNull() {
-        return supplier.get();
-    }
-
-    /**
-     * Returns whether this ref is attached to a database context and capable of fetching the record on demand.
-     *
-     * @return {@code true}, this implementation is created attached to a database context.
-     */
-    @Override
-    public boolean isFetchable() {
-        return true;
-    }
-
-    /**
-     * Returns a detached ref with the same identity but without data. The returned ref is not attached to a
-     * database context. To obtain an attached ref that can re-fetch the record, use
-     * {@link EntityRepository#unload(Entity) EntityRepository.unload()} instead.
-     *
-     * @return a detached ref with the same type and primary key but without cached data.
-     */
-    @Override
-    public Ref<T> unload() {
-        return Ref.of(type, pk);
+        super(supplier, type, pk);
     }
 
     @Override
     public int hashCode() {
-        return RowIdentity.hash(type, pk);
+        return RowIdentity.hash(type(), id());
     }
 
     @Override
@@ -126,19 +52,19 @@ public boolean equals(Object obj) {
         if (obj instanceof ScalarRefImpl<?, ?> other) {
             // Both sides hold their identity as the raw pk of a class that is its own row identity; the type gate guarantees the
             // pk classes match.
-            return Objects.equals(type, other.type) && pk.equals(other.pk);
+            return Objects.equals(type(), other.type()) && id().equals(other.id());
         }
         if (obj instanceof Ref<?> l) {
-            return RowIdentity.refEquals(type, pk, l);
+            return RowIdentity.refEquals(type(), id(), l);
         }
         return false;
     }
 
     @Override
     public String toString() {
-        Class<?> type = this.type;
+        Class<?> type = type();
         return type == Record.class
-                ? "%s".formatted(pk)
-                : "%s@%s".formatted(type.getSimpleName(), pk);
+                ? "%s".formatted(id())
+                : "%s@%s".formatted(type.getSimpleName(), id());
     }
 }
diff --git a/storm-core/src/main/java/st/orm/core/spi/TransactionScope.java b/storm-core/src/main/java/st/orm/core/spi/TransactionScope.java
index 947310183..50970468c 100644
--- a/storm-core/src/main/java/st/orm/core/spi/TransactionScope.java
+++ b/storm-core/src/main/java/st/orm/core/spi/TransactionScope.java
@@ -144,11 +144,7 @@ public static TransactionScope create(Options options, @Nullable TransactionScop
      * path are not observed.
      */
     public static @Nullable TransactionContext resolveContext(TransactionTemplateProvider provider) {
-        var scope = CURRENT.get();
-        if (scope != null) {
-            return scope.getOrMaterializeContext(provider);
-        }
-        return provider.getTransactionTemplate().currentContext().orElse(null);
+        return resolveContext(provider, null);
     }
 
     /**
diff --git a/storm-core/src/main/java/st/orm/core/template/QueryBuilder.java b/storm-core/src/main/java/st/orm/core/template/QueryBuilder.java
index 21317de46..e38bb10c9 100644
--- a/storm-core/src/main/java/st/orm/core/template/QueryBuilder.java
+++ b/storm-core/src/main/java/st/orm/core/template/QueryBuilder.java
@@ -352,15 +352,6 @@ public final <V extends Data> QueryBuilder<T, R, ID> where(Navigable<? extends T
         return where(path.asMetamodel(), EQUALS, record);
     }
 
-    @SuppressWarnings("unchecked")
-    private static <T extends Data> Metamodel<?, ?>[] asMetamodels(Navigable<? extends T, ?>[] paths) {
-        Metamodel<?, ?>[] result = new Metamodel[paths.length];
-        for (int i = 0; i < paths.length; i++) {
-            result[i] = paths[i].asMetamodel();
-        }
-        return result;
-    }
-
     /**
      * Adds a WHERE clause that matches the specified ref. The ref can represent any of the related tables in the
      * table graph.
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/DeleteBuilderImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/DeleteBuilderImpl.java
index 07368bd5c..bd34b81f9 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/DeleteBuilderImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/DeleteBuilderImpl.java
@@ -195,24 +195,7 @@ private TemplateString toTemplateString() {
         } else {
             template = TemplateString.combine(TemplateString.of("SELECT "), getPrimaryKeyTemplate(true), TemplateString.raw("\nFROM \0", from(fromType, true)));
         }
-        //noinspection DuplicatedCode
-        if (!join.isEmpty()) {
-            template = join.stream()
-                    .reduce(template,
-                            (acc, join) -> TemplateString.combine(acc, wrap(join)),
-                            TemplateString::combine);
-        }
-        if (!where.isEmpty()) {
-            if (where.size() == 1) {
-                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), wrap(where.getFirst()));
-            } else {
-                TemplateString whereClause = where.stream()
-                        .map(w -> TemplateString.combine(TemplateString.of("("), wrap(w), TemplateString.of(")")))
-                        .reduce((a, b) -> TemplateString.combine(a, TemplateString.of("\n  AND "), b))
-                        .orElseThrow();
-                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), whereClause);
-            }
-        }
+        template = appendJoinsAndWhere(template);
         if (!supportsJoin()) {
             template = TemplateString.combine(TemplateString.raw("DELETE\nFROM \0\nWHERE (", from(fromType, false)),
                     getPrimaryKeyTemplate(false), TemplateString.of(") IN ("), wrap(subquery(template, false)), TemplateString.of(")"));
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/ObjectMapperFactory.java b/storm-core/src/main/java/st/orm/core/template/impl/ObjectMapperFactory.java
index 5aba68695..382efed2f 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/ObjectMapperFactory.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/ObjectMapperFactory.java
@@ -37,8 +37,6 @@
 import st.orm.PK;
 import st.orm.core.spi.Instantiators;
 import st.orm.core.spi.Nullability;
-import st.orm.core.spi.ORMReflection;
-import st.orm.core.spi.Providers;
 import st.orm.core.spi.RefFactory;
 import st.orm.core.template.SqlTemplateException;
 import st.orm.mapping.Instantiator;
@@ -48,8 +46,6 @@
  */
 public final class ObjectMapperFactory {
 
-    private static final ORMReflection REFLECTION = Providers.getORMReflection();
-
     private ObjectMapperFactory() {
     }
 
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/PredicateBuilderFactory.java b/storm-core/src/main/java/st/orm/core/template/impl/PredicateBuilderFactory.java
index 20077fff6..45f1bbc1a 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/PredicateBuilderFactory.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/PredicateBuilderFactory.java
@@ -89,22 +89,4 @@ static <T extends Data, R, ID, V> PredicateBuilder<T, R, ID> createWithId(
             Iterable<V> o) {
         return new PredicateBuilderImpl<>(wrap(new ObjectExpression(path, operator, o)));
     }
-    /**
-     * Creates a new instance of {@link PredicateBuilder} for the specified path, operator, and values with an ID.
-     *
-     * @param path the metamodel path representing the field to be queried
-     * @param operator the operator to be used in the predicate
-     * @param o the values to be used in the predicate
-     * @param <T> the type of the record
-     * @param <R> the type of the result
-     * @param <ID> the type of the ID
-     * @param <V> the type of the values
-     * @return a new instance of {@link PredicateBuilder}
-     */
-    static <T extends Data, R, ID, V extends Data> PredicateBuilder<T, R, ID> createRefWithId(
-            Metamodel<?, V> path,
-            Operator operator,
-            Iterable<Ref<V>> o) {
-        return new PredicateBuilderImpl<>(wrap(new ObjectExpression(path, operator, o)));
-    }
 }
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/PreparedStatementTemplateImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/PreparedStatementTemplateImpl.java
index 3f2f13e3a..18fe61706 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/PreparedStatementTemplateImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/PreparedStatementTemplateImpl.java
@@ -43,7 +43,6 @@
 import java.util.List;
 import java.util.TimeZone;
 import java.util.UUID;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
@@ -572,24 +571,6 @@ private static void setParameters(PreparedStatement preparedStatement,
         }
     }
 
-    @FunctionalInterface
-    interface SqlRunnable { void run() throws SQLException; }
-
-    private static void setObjectOr(PreparedStatement ps,
-                                    AtomicBoolean supportsSetObject,
-                                    SqlRunnable typedSetter,
-                                    SqlRunnable legacyFallback) throws SQLException {
-        if (supportsSetObject.get()) {
-            try {
-                typedSetter.run();
-                return;
-            } catch (SQLFeatureNotSupportedException e) {
-                supportsSetObject.set(false);
-            }
-        }
-        legacyFallback.run();
-    }
-
     @Override
     public @Nullable DataSource dataSource() {
         return dataSource;
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/QueryBuilderImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/QueryBuilderImpl.java
index 884631c19..4cbf375bc 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/QueryBuilderImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/QueryBuilderImpl.java
@@ -176,6 +176,31 @@ abstract QueryBuilder<T, R, ID> copyWith(QueryTemplate queryTemplate,
      */
     protected abstract boolean supportsJoin();
 
+    /**
+     * Appends the registered joins and the WHERE clause, with multiple where-conditions AND-ed together, to the
+     * given template.
+     */
+    protected final TemplateString appendJoinsAndWhere(TemplateString template) {
+        if (!join.isEmpty()) {
+            template = join.stream()
+                    .reduce(template,
+                            (acc, join) -> TemplateString.combine(acc, wrap(join)),
+                            TemplateString::combine);
+        }
+        if (!where.isEmpty()) {
+            if (where.size() == 1) {
+                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), wrap(where.getFirst()));
+            } else {
+                TemplateString whereClause = where.stream()
+                        .map(w -> TemplateString.combine(TemplateString.of("("), wrap(w), TemplateString.of(")")))
+                        .reduce((a, b) -> TemplateString.combine(a, TemplateString.of("\n  AND "), b))
+                        .orElseThrow();
+                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), whereClause);
+            }
+        }
+        return template;
+    }
+
     /**
      * Resolving a reference selects the referenced table's columns into the row that holds the reference, which only a
      * statement that selects rows can do.
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/QueryModelImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/QueryModelImpl.java
index 12fdee18b..402486185 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/QueryModelImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/QueryModelImpl.java
@@ -607,7 +607,7 @@ private static boolean isPrimitiveCompatible(Object o, Class<?> clazz) {
      * @return the resolved value.
      * @throws SqlTemplateException if the value is invalid in this context.
      */
-    private Object resolveElements(@Nullable Object value) throws SqlTemplateException {
+    private @Nullable Object resolveElements(@Nullable Object value) throws SqlTemplateException {
         return switch (value) {
             case TemplateString ignore -> throw new SqlTemplateException("TemplateString is not allowed as a string template value.");
             case Stream<?> ignore -> throw new SqlTemplateException("Stream is not supported as a string template value. Collect the Stream into a List before passing it.");
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/RecordMapper.java b/storm-core/src/main/java/st/orm/core/template/impl/RecordMapper.java
index cebb9c79d..683deb9ff 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/RecordMapper.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/RecordMapper.java
@@ -1272,9 +1272,12 @@ private static RecordStep recordStep(RecordField field,
      * @return the reader for the target's primary key.
      * @throws SqlTemplateException if the type declares no primary key.
      */
-    private static KeyReader keyReader(RecordType type, FetchPlan fetchPlan) throws SqlTemplateException {
-        RecordField pkField = findPkField(type.type()).orElseThrow(() -> new SqlTemplateException(
-                "Cannot resolve a reference to %s: the type declares no primary key.".formatted(type.type().getSimpleName())));
+    /**
+     * Returns the flat column offset of the primary key field: the sum of the column counts of all fields
+     * preceding it.
+     */
+    private static int pkColumnOffset(RecordType type, RecordField pkField, FetchPlan fetchPlan)
+            throws SqlTemplateException {
         int offset = 0;
         for (RecordField field : type.fields()) {
             if (field.name().equals(pkField.name())) {
@@ -1282,6 +1285,13 @@ private static KeyReader keyReader(RecordType type, FetchPlan fetchPlan) throws
             }
             offset += getFieldColumnCount(field, fetchPlan);
         }
+        return offset;
+    }
+
+    private static KeyReader keyReader(RecordType type, FetchPlan fetchPlan) throws SqlTemplateException {
+        RecordField pkField = findPkField(type.type()).orElseThrow(() -> new SqlTemplateException(
+                "Cannot resolve a reference to %s: the type declares no primary key.".formatted(type.type().getSimpleName())));
+        int offset = pkColumnOffset(type, pkField, fetchPlan);
         int columnCount = getFieldColumnCount(pkField, fetchPlan);
         Constructor<?> keyConstructor = null;
         if (columnCount > 1) {
@@ -1401,14 +1411,7 @@ private static PkInfo calculatePkInfo(RecordType type, FetchPlan fetchPlan) thro
             return PkInfo.NONE;
         }
         RecordField pkField = pkFieldOpt.get();
-        // Calculate the offset: sum of column counts for all fields before the PK field.
-        int offset = 0;
-        for (RecordField field : type.fields()) {
-            if (field.name().equals(pkField.name())) {
-                break;
-            }
-            offset += getFieldColumnCount(field, fetchPlan);
-        }
+        int offset = pkColumnOffset(type, pkField, fetchPlan);
         // Calculate how many columns the PK spans.
         int pkColumnCount = getFieldColumnCount(pkField, fetchPlan);
         // For composite PKs (record types), we need the constructor.
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/RecordValidation.java b/storm-core/src/main/java/st/orm/core/template/impl/RecordValidation.java
index 11e3ec87f..eaafac6d8 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/RecordValidation.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/RecordValidation.java
@@ -54,8 +54,6 @@
 import st.orm.Ref;
 import st.orm.StormConfig;
 import st.orm.Version;
-import st.orm.core.spi.ORMReflection;
-import st.orm.core.spi.Providers;
 import st.orm.core.spi.TypeDiscovery;
 import st.orm.core.template.SqlTemplate;
 import st.orm.core.template.SqlTemplate.Parameter;
@@ -70,7 +68,6 @@
 @SuppressWarnings("ALL")
 final class RecordValidation {
 
-    private static final ORMReflection REFLECTION = Providers.getORMReflection();
     private static final Logger LOGGER = LoggerFactory.getLogger("st.orm.validation");
 
     private RecordValidation() {
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/SchemaValidator.java b/storm-core/src/main/java/st/orm/core/template/impl/SchemaValidator.java
index ba50c0153..32cacdbec 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/SchemaValidator.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/SchemaValidator.java
@@ -255,9 +255,7 @@ public List<String> validateAndReport(Iterable<Class<? extends Data>> types, boo
      * <p>This is a convenience method for "warn" mode: validation issues are logged but never cause an exception.</p>
      */
     public void validateOrWarn() {
-        LOGGER.info("Validating Data types for schema compatibility.");
-        List<Class<? extends Data>> types = TypeDiscovery.getDataTypes();
-        reportErrors(validate(types), false, types.size());
+        validateAndReport(false);
     }
 
     /**
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/SelectBuilderImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/SelectBuilderImpl.java
index d458110fb..ef7e0362b 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/SelectBuilderImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/SelectBuilderImpl.java
@@ -254,24 +254,7 @@ private TemplateString toTemplateString(TemplateString selectClause, boolean wit
         if (hasLock && queryTemplate.dialect().applyLockHintAfterFrom()) {
             template = TemplateString.combine(template, TemplateString.of("\n"), forLock);
         }
-        //noinspection DuplicatedCode
-        if (!join.isEmpty()) {
-            template = join.stream()
-                    .reduce(template,
-                            (acc, join) -> TemplateString.combine(acc, wrap(join)),
-                            TemplateString::combine);
-        }
-        if (!where.isEmpty()) {
-            if (where.size() == 1) {
-                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), wrap(where.getFirst()));
-            } else {
-                TemplateString whereClause = where.stream()
-                        .map(w -> TemplateString.combine(TemplateString.of("("), wrap(w), TemplateString.of(")")))
-                        .reduce((a, b) -> TemplateString.combine(a, TemplateString.of("\n  AND "), b))
-                        .orElseThrow();
-                template = TemplateString.combine(template, TemplateString.of("\nWHERE "), whereClause);
-            }
-        }
+        template = appendJoinsAndWhere(template);
         if (!groupBy.isEmpty()) {
             TemplateString groupByClause = groupBy.stream()
                     .reduce((a, b) -> TemplateString.combine(a, TemplateString.of(", "), b))
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/SqlInterceptorManager.java b/storm-core/src/main/java/st/orm/core/template/impl/SqlInterceptorManager.java
index 0d0c8f4b7..523b3b505 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/SqlInterceptorManager.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/SqlInterceptorManager.java
@@ -226,13 +226,7 @@ private SqlInterceptorManager() {
      * @param interceptor the interceptor to call for each SQL statement.
      */
     public static void registerGlobalInterceptor(UnaryOperator<Sql> interceptor) {
-        LOCK.writeLock().lock();
-        try {
-            GLOBAL_OPERATORS.add(interceptor);
-            globalOperatorCount = GLOBAL_OPERATORS.size();
-        } finally {
-            LOCK.writeLock().unlock();
-        }
+        addGlobalOperator(interceptor);
     }
 
     /**
@@ -241,13 +235,7 @@ public static void registerGlobalInterceptor(UnaryOperator<Sql> interceptor) {
      * @param observer the observer to call for each SQL statement.
      */
     public static void registerGlobalObserver(Consumer<Sql> observer) {
-        LOCK.writeLock().lock();
-        try {
-            GLOBAL_OPERATORS.add(observer);
-            globalOperatorCount = GLOBAL_OPERATORS.size();
-        } finally {
-            LOCK.writeLock().unlock();
-        }
+        addGlobalOperator(observer);
     }
 
     /**
@@ -256,13 +244,7 @@ public static void registerGlobalObserver(Consumer<Sql> observer) {
      * @param observer the observer to unregister.
      */
     public static void unregisterGlobalObserver(UnaryOperator<Sql> observer) {
-        LOCK.writeLock().lock();
-        try {
-            GLOBAL_OPERATORS.remove(observer);
-            globalOperatorCount = GLOBAL_OPERATORS.size();
-        } finally {
-            LOCK.writeLock().unlock();
-        }
+        removeGlobalOperator(observer);
     }
 
     /**
@@ -271,9 +253,23 @@ public static void unregisterGlobalObserver(UnaryOperator<Sql> observer) {
      * @param observer the observer to unregister.
      */
     public static void unregisterGlobalObserver(Consumer<Sql> observer) {
+        removeGlobalOperator(observer);
+    }
+
+    private static void addGlobalOperator(Object operator) {
+        LOCK.writeLock().lock();
+        try {
+            GLOBAL_OPERATORS.add(operator);
+            globalOperatorCount = GLOBAL_OPERATORS.size();
+        } finally {
+            LOCK.writeLock().unlock();
+        }
+    }
+
+    private static void removeGlobalOperator(Object operator) {
         LOCK.writeLock().lock();
         try {
-            GLOBAL_OPERATORS.remove(observer);
+            GLOBAL_OPERATORS.remove(operator);
             globalOperatorCount = GLOBAL_OPERATORS.size();
         } finally {
             LOCK.writeLock().unlock();
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/SqlTemplateImpl.java b/storm-core/src/main/java/st/orm/core/template/impl/SqlTemplateImpl.java
index b63237a6c..4f46dde33 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/SqlTemplateImpl.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/SqlTemplateImpl.java
@@ -474,74 +474,60 @@ Sql process(TemplateString template, boolean applyInterceptors) throws SqlTempla
      * that differ only in how far a collection expanded share it.
      */
     private Object getShapeKey(BindingContext bindingContext) {
-        try {
-            var fragments = bindingContext.fragments();
-            var elements = bindingContext.elements();
-            var shapeGenerator = shapeGenerator();
-            var shapeKey = new ArrayList<>(fragments.size() + elements.size());
-            for (int i = 0, size = fragments.size(); i < size; i++) {
-                shapeKey.add(fragments.get(i));
-                if (i < elements.size()) {
-                    var element = elements.get(i);
-                    if (element instanceof Wrapped(var wrapped)) {
-                        for (var e : wrapped) {
-                            if (!e.synthetic()) {
-                                var key = getElementProcessor(e.element()).getShapeKey(e.element(), shapeGenerator);
-                                if (key != null) {
-                                    shapeKey.add(key);
-                                } else {
-                                    return null;
-                                }
-                            }
-                        }
-                    } else {
-                        var key = getElementProcessor(element).getShapeKey(element, shapeGenerator);
-                        if (key != null) {
-                            shapeKey.add(key);
-                        } else {
-                            return null;
-                        }
-                    }
-                }
-            }
-            return shapeKey;
-        } catch (SqlTemplateException e) {
-            throw new UncheckedSqlTemplateException(e);
-        }
+        var shapeGenerator = shapeGenerator();
+        return buildKey(bindingContext,
+                element -> getElementProcessor(element).getShapeKey(element, shapeGenerator));
     }
 
     private Object getCompilationKey(BindingContext bindingContext) {
+        return buildKey(bindingContext,
+                element -> getElementProcessor(element).getCompilationKey(element, keyGenerator));
+    }
+
+    /**
+     * The per-element contribution to a template key, or {@code null} when the element does not support keying.
+     */
+    @FunctionalInterface
+    private interface KeyExtractor {
+        @Nullable Object apply(Element element) throws SqlTemplateException;
+    }
+
+    /**
+     * Interleaves the template's fragments with the per-element keys the extractor produces, or returns
+     * {@code null} as soon as any element yields no key.
+     */
+    private @Nullable Object buildKey(BindingContext bindingContext, KeyExtractor extractor) {
         try {
             var fragments = bindingContext.fragments();
             var elements = bindingContext.elements();
             // Runs for every processed template; sized for the common case of one key per fragment and element.
-            var compilationKey = new ArrayList<>(fragments.size() + elements.size());
+            var templateKey = new ArrayList<>(fragments.size() + elements.size());
             for (int i = 0, size = fragments.size(); i < size; i++) {
-                compilationKey.add(fragments.get(i));
+                templateKey.add(fragments.get(i));
                 if (i < elements.size()) {
                     var element = elements.get(i);
                     if (element instanceof Wrapped(var wrapped)) {
                         for (var e : wrapped) {
-                            if (!e.synthetic()) {   // Ignore synthetic elements for the compilation key.
-                                var key = getElementProcessor(e.element()).getCompilationKey(e.element(), keyGenerator);
+                            if (!e.synthetic()) {   // Ignore synthetic elements for the key.
+                                var key = extractor.apply(e.element());
                                 if (key != null) {
-                                    compilationKey.add(key);
+                                    templateKey.add(key);
                                 } else {
                                     return null;
                                 }
                             }
                         }
                     } else {
-                        var key = getElementProcessor(element).getCompilationKey(element, keyGenerator);
+                        var key = extractor.apply(element);
                         if (key != null) {
-                            compilationKey.add(key);
+                            templateKey.add(key);
                         } else {
                             return null;
                         }
                     }
                 }
             }
-            return compilationKey;
+            return templateKey;
         } catch (SqlTemplateException e) {
             throw new UncheckedSqlTemplateException(e);
         }
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/TemplatePreparation.java b/storm-core/src/main/java/st/orm/core/template/impl/TemplatePreparation.java
index 412ba29fe..861dfa7b0 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/TemplatePreparation.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/TemplatePreparation.java
@@ -330,15 +330,7 @@ private Element resolveObjectElement(
     ) throws SqlTemplateException {
         String previous = removeComments(previousFragment, template.dialect()).stripTrailing().toUpperCase();
         return switch (operation) {
-            case SELECT, DELETE, UNDEFINED -> {
-                if (endsWithKeyword(previous, "WHERE")) {
-                    if (o != null) {
-                        yield where(o);
-                    }
-                    throw new SqlTemplateException("Non-null object expected after WHERE.");
-                }
-                yield param(o);
-            }
+            case SELECT, DELETE, UNDEFINED -> whereOrParam(previous, o);
             case INSERT -> {
                 if (endsWithKeyword(previous, "VALUES")) {
                     if (o instanceof Data r) {
@@ -346,13 +338,7 @@ private Element resolveObjectElement(
                     }
                     throw new SqlTemplateException("Record expected after VALUES.");
                 }
-                if (endsWithKeyword(previous, "WHERE")) {
-                    if (o != null) {
-                        yield where(o);
-                    }
-                    throw new SqlTemplateException("Non-null object expected after WHERE.");
-                }
-                yield param(o);
+                yield whereOrParam(previous, o);
             }
             case UPDATE -> {
                 if (endsWithKeyword(previous, "SET")) {
@@ -361,17 +347,25 @@ private Element resolveObjectElement(
                     }
                     throw new SqlTemplateException("Record expected after SET.");
                 }
-                if (endsWithKeyword(previous, "WHERE")) {
-                    if (o != null) {
-                        yield where(o);
-                    }
-                    throw new SqlTemplateException("Non-null object expected after WHERE.");
-                }
-                yield param(o);
+                yield whereOrParam(previous, o);
             }
         };
     }
 
+    /**
+     * Resolves an object in a position where a where-object is accepted: after WHERE the object becomes a
+     * where-element (and must be non-null), anywhere else it becomes a parameter.
+     */
+    private Element whereOrParam(String previous, @Nullable Object o) throws SqlTemplateException {
+        if (endsWithKeyword(previous, "WHERE")) {
+            if (o != null) {
+                return where(o);
+            }
+            throw new SqlTemplateException("Non-null object expected after WHERE.");
+        }
+        return param(o);
+    }
+
     /**
      * Resolves an array value into an element.
      *
@@ -1170,19 +1164,7 @@ private void deriveAutoJoins(
                 if (beyondRef && !isReferencedBeyond(referenced.joined(), pkPath)) {
                     continue;
                 }
-                String fromAlias;
-                if (fkName == null) {
-                    fromAlias = aliasMapper.getAlias(
-                            table,
-                            fkPath,
-                            INNER,
-                            template.dialect(),
-                            () -> new SqlTemplateException("Table %s for From not found at path %s."
-                                    .formatted(type.type().getSimpleName(), fkPath))
-                    );
-                } else {
-                    fromAlias = fkName;
-                }
+                String fromAlias = resolveFromAlias(fkName, table, fkPath, type, aliasMapper);
                 RecordType fieldType = getRecordType(field.type());
                 boolean effectiveOuterJoin = outerJoin || field.nullable();
                 String alias = addForeignKeyJoin(table, rootTable, field, fieldType, fromAlias, fkPath,
@@ -1198,24 +1180,36 @@ private void deriveAutoJoins(
                 if (beyondRef && !isReferencedBeyond(referenced.joined(), pkPath)) {
                     continue;
                 }
-                String fromAlias;
-                if (fkName == null) {
-                    fromAlias = aliasMapper.getAlias(
-                            table,
-                            fkPath,
-                            INNER,
-                            template.dialect(),
-                            () -> new SqlTemplateException("Table %s for From not found at path %s."
-                                    .formatted(type.type().getSimpleName(), fkPath))
-                    );
-                } else {
-                    fromAlias = fkName;
-                }
+                String fromAlias = resolveFromAlias(fkName, table, fkPath, type, aliasMapper);
                 deriveAutoJoins(getRecordType(field.type()), table, copy, fromAlias, outerJoin, beyondRef, context);
             }
         }
     }
 
+    /**
+     * Resolves the alias a derived join starts from: the enclosing foreign key's name when the traversal is inside
+     * one, or the alias registered for the table at the foreign key path otherwise.
+     */
+    private String resolveFromAlias(
+            @Nullable String fkName,
+            Class<? extends Data> table,
+            String fkPath,
+            RecordType type,
+            AliasMapper aliasMapper
+    ) throws SqlTemplateException {
+        if (fkName != null) {
+            return fkName;
+        }
+        return aliasMapper.getAlias(
+                table,
+                fkPath,
+                INNER,
+                template.dialect(),
+                () -> new SqlTemplateException("Table %s for From not found at path %s."
+                        .formatted(type.type().getSimpleName(), fkPath))
+        );
+    }
+
     /**
      * Generates a foreign key join from {@code fromAlias} on {@code table} to the table backing {@code fieldType},
      * registers the new alias and foreign key mapping, and appends the join to {@code joins}. The join is marked as an
diff --git a/storm-core/src/main/java/st/orm/core/template/impl/TemplateProcessor.java b/storm-core/src/main/java/st/orm/core/template/impl/TemplateProcessor.java
index 1b91ea1bd..04d078ff1 100644
--- a/storm-core/src/main/java/st/orm/core/template/impl/TemplateProcessor.java
+++ b/storm-core/src/main/java/st/orm/core/template/impl/TemplateProcessor.java
@@ -1054,19 +1054,7 @@ private final class BindingSession implements TemplateBinder {
          * @throws SqlTemplateException if binding fails.
          */
         void bindElements(BindingContext context) throws SqlTemplateException {
-            for (Element element : context.elements()) {
-                if (element instanceof Wrapped(var wrapped)) {
-                    for (var e : wrapped) {
-                        if (!e.synthetic()) {
-                            var hint = nextHint();
-                            getElementProcessor(e.element()).bind(e.element(), this, hint);
-                        }
-                    }
-                } else {
-                    var hint = nextHint();
-                    getElementProcessor(element).bind(element, this, hint);
-                }
-            }
+            bindAll(context.elements());
             if (hintCursor != bindHints.size()) {
                 throw new UncheckedSqlTemplateException(new SqlTemplateException(
                         "Bind hint consumption mismatch. Used %d hints but %d were produced."
@@ -1118,7 +1106,14 @@ private void assertAllHintsConsumed() {
          * @throws SqlTemplateException if binding fails.
          */
         private void bindPreparedAttached(PreparedTemplate preparedTemplate) throws SqlTemplateException {
-            for (var element : preparedTemplate.context().elements()) {
+            bindAll(preparedTemplate.context().elements());
+        }
+
+        /**
+         * Binds the given elements, consuming a bind hint from the shared tape for each non-synthetic element.
+         */
+        private void bindAll(List<Element> elements) throws SqlTemplateException {
+            for (Element element : elements) {
                 if (element instanceof Wrapped(var wrapped)) {
                     for (var e : wrapped) {
                         if (!e.synthetic()) {
diff --git a/storm-foundation/src/main/java/st/orm/LoadedRef.java b/storm-foundation/src/main/java/st/orm/LoadedRef.java
new file mode 100644
index 000000000..424457345
--- /dev/null
+++ b/storm-foundation/src/main/java/st/orm/LoadedRef.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2024 - 2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package st.orm;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Detached {@link Ref} implementation wrapping an already loaded record along with its row identity.
+ *
+ * <p>The id is stored rather than derived so one implementation serves both entities, whose id comes from the
+ * record itself, and projections, whose row identity is supplied separately. The ref is not attached to a
+ * database context; the wrapped record is all it can return.</p>
+ *
+ * @param <T> record type.
+ * @since 1.14
+ */
+final class LoadedRef<T extends Data> extends AbstractRef<T> {
+    private final T value;
+    private final Object id;
+
+    LoadedRef(T value, Object id) {
+        this.value = requireNonNull(value, "value");
+        this.id = id;
+    }
+
+    @Override
+    public Class<T> type() {
+        //noinspection unchecked
+        return (Class<T>) value.getClass();
+    }
+
+    @Override
+    public Object id() {
+        return id;
+    }
+
+    @Override
+    public T getOrNull() {
+        return value;
+    }
+
+    @Override
+    public T fetchOrNull() {
+        return value;
+    }
+
+    @Override
+    public boolean isFetchable() {
+        return false;
+    }
+
+    @Override
+    public Ref<T> unload() {
+        return Ref.of(type(), id());
+    }
+}
diff --git a/storm-foundation/src/main/java/st/orm/Ref.java b/storm-foundation/src/main/java/st/orm/Ref.java
index db51c3642..40db58877 100644
--- a/storm-foundation/src/main/java/st/orm/Ref.java
+++ b/storm-foundation/src/main/java/st/orm/Ref.java
@@ -75,46 +75,8 @@ static <T extends Data, ID> Ref<T> of(Class<T> type, ID pk) {
      * @return a fully loaded ref instance for the provided entity.
      */
     static <E extends Entity<?>> Ref<E> of(E entity) {
-        class DetachedEntity<TE extends Entity<?>> extends AbstractRef<TE> {
-            private final TE entity;
-
-            DetachedEntity(TE entity) {
-                requireNonNull(entity, "Entity cannot be null.");
-                this.entity = entity;
-            }
-
-            @Override
-            public Class<TE> type() {
-                //noinspection unchecked
-                return (Class<TE>) entity.getClass();
-            }
-
-            @Override
-            public Object id() {
-                return entity.id();
-            }
-
-            @Override
-            public TE getOrNull() {
-                return entity;
-            }
-
-            @Override
-            public TE fetchOrNull() {
-                return entity;
-            }
-
-            @Override
-            public boolean isFetchable() {
-                return false;
-            }
-
-            @Override
-            public Ref<TE> unload() {
-                return Ref.of(type(), id());
-            }
-        }
-        return new DetachedEntity<>(entity);
+        requireNonNull(entity, "Entity cannot be null.");
+        return new LoadedRef<>(entity, entity.id());
     }
 
     /**
@@ -132,47 +94,9 @@ public Ref<TE> unload() {
      * @return a fully loaded ref instance for the provided projection.
      */
     static <P extends Projection<ID>, ID> Ref<P> of(P projection, ID id) {
-        class DetachedProjection<TE extends Projection<TID>, TID> extends AbstractRef<TE> {
-            private final TID id;
-            private final TE projection;
-
-            DetachedProjection(TID id, TE projection) {
-                this.id = requireNonNull(id, "ID cannot be null.");
-                this.projection = requireNonNull(projection, "Projection cannot be null.");
-            }
-
-            @Override
-            public Class<TE> type() {
-                //noinspection unchecked
-                return (Class<TE>) projection.getClass();
-            }
-
-            @Override
-            public Object id() {
-                return id;
-            }
-
-            @Override
-            public TE getOrNull() {
-                return projection;
-            }
-
-            @Override
-            public TE fetchOrNull() {
-                return projection;
-            }
-
-            @Override
-            public boolean isFetchable() {
-                return false;
-            }
-
-            @Override
-            public Ref<TE> unload() {
-                return Ref.of(type(), id());
-            }
-        }
-        return new DetachedProjection<>(id, projection);
+        requireNonNull(id, "ID cannot be null.");
+        requireNonNull(projection, "Projection cannot be null.");
+        return new LoadedRef<>(projection, id);
     }
 
     /**
diff --git a/storm-h2/pom.xml b/storm-h2/pom.xml
index 100e2d5a8..ff2de8c12 100644
--- a/storm-h2/pom.xml
+++ b/storm-h2/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.h2.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -101,6 +101,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-h2/src/main/java/st/orm/spi/h2/H2SqlDialect.java b/storm-h2/src/main/java/st/orm/spi/h2/H2SqlDialect.java
index 9cc1cd967..e95e080bb 100644
--- a/storm-h2/src/main/java/st/orm/spi/h2/H2SqlDialect.java
+++ b/storm-h2/src/main/java/st/orm/spi/h2/H2SqlDialect.java
@@ -26,14 +26,12 @@
 import java.sql.SQLException;
 import java.util.Set;
 import java.util.UUID;
-import java.util.regex.Pattern;
 import java.util.stream.Stream;
 import st.orm.Operator;
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
-import st.orm.core.template.SqlDialect;
 
-public class H2SqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class H2SqlDialect extends DefaultSqlDialect {
 
     public H2SqlDialect() {
     }
@@ -53,14 +51,6 @@ public String name() {
         return "H2";
     }
 
-    /**
-     * H2 does not support aliasing the target table in DELETE statements.
-     */
-    @Override
-    public boolean supportsDeleteAlias() {
-        return false;
-    }
-
     /**
      * H2 supports multi-value tuples in the IN clause.
      */
@@ -69,19 +59,6 @@ public boolean supportsMultiValueTuples() {
         return true;
     }
 
-    private static final Pattern H2_IDENTIFIER = Pattern.compile("^[A-Za-z][A-Za-z0-9_]*$");
-
-    /**
-     * Returns the pattern for valid identifiers.
-     *
-     * @return the pattern for valid identifiers.
-     * @since 1.11
-     */
-    @Override
-    public Pattern getValidIdentifierPattern() {
-        return H2_IDENTIFIER;
-    }
-
     private static final Set<String> H2_KEYWORDS = Stream.concat(ANSI_KEYWORDS.stream(), Stream.of(
             "AUTOINCREMENT", "CACHED", "EXPLAIN", "IF", "ILIKE", "INDEX", "KEY", "LIMIT",
             "MEMORY", "MINUS", "OFFSET", "QUALIFY", "REGEXP", "ROWNUM", "SYSDATE", "SYSTIME",
@@ -111,40 +88,6 @@ public String escape(String name) {
         return "\"%s\"".formatted(name.replace("\"", "\"\""));
     }
 
-    /**
-     * Regex for double-quoted identifiers (handling doubled double quotes as escapes).
-     */
-    private static final Pattern IDENTIFIER_PATTERN = Pattern.compile(
-            "\"(?:\"\"|[^\"])*\""
-    );
-
-    /**
-     * Returns the pattern for identifiers.
-     *
-     * @return the pattern for identifiers.
-     */
-    @Override
-    public Pattern getIdentifierPattern() {
-        return IDENTIFIER_PATTERN;
-    }
-
-    /**
-     * Regex for single-quoted string literals, handling both doubled single quotes and backslash escapes.
-     */
-    private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile(
-            "'(?:''|\\\\.|[^'\\\\])*'"
-    );
-
-    /**
-     * Returns the pattern for string literals.
-     *
-     * @return the pattern for string literals.
-     */
-    @Override
-    public Pattern getQuoteLiteralPattern() {
-        return QUOTE_LITERAL_PATTERN;
-    }
-
     /**
      * Returns whether a multi-column comparison renders as a row value tuple, which for H2 is the case for an
      * ordering comparison and for a multi-row list.
@@ -229,16 +172,6 @@ public String forShareLockHint() {
         return "";
     }
 
-    /**
-     * Returns the lock hint for a write lock.
-     *
-     * @return the lock hint for a write lock.
-     */
-    @Override
-    public String forUpdateLockHint() {
-        return "FOR UPDATE";
-    }
-
     /**
      * Sets a UUID parameter using {@link PreparedStatement#setObject(int, Object)}, which allows the H2 JDBC
      * driver to bind the value as a native UUID type.
diff --git a/storm-h2/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-h2/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index f0d44d863..b51953f70 100644
--- a/storm-h2/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-h2/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.h2.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-jackson2/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java b/storm-jackson2/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
index 0468b5995..cfc8dfd0b 100644
--- a/storm-jackson2/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
+++ b/storm-jackson2/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
@@ -227,7 +227,7 @@ public Object fromDatabase(Object[] values, RefFactory refFactory) throws SqlTem
         RefFactory outerRefFactory = REF_FACTORY.get();
         REF_FACTORY.set(refFactory);
         try {
-            return mapper.readValue((String) values[0], typeReference);
+            return mapper.readValue((String) value, typeReference);
         } catch (JsonProcessingException e) {
             throw new SqlTemplateException(e);
         } finally {
diff --git a/storm-jackson3/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java b/storm-jackson3/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
index b6abb0445..2ef9a98bb 100644
--- a/storm-jackson3/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
+++ b/storm-jackson3/src/main/java/st/orm/jackson/spi/JsonORMConverterImpl.java
@@ -227,7 +227,7 @@ public Object fromDatabase(Object[] values, RefFactory refFactory) throws SqlTem
         RefFactory outerRefFactory = REF_FACTORY.get();
         REF_FACTORY.set(refFactory);
         try {
-            return mapper.readValue((String) values[0], typeReference);
+            return mapper.readValue((String) value, typeReference);
         } catch (JacksonException e) {
             throw new SqlTemplateException(e);
         } finally {
diff --git a/storm-java21/src/main/java/st/orm/repository/impl/EntityRepositoryImpl.java b/storm-java21/src/main/java/st/orm/repository/impl/EntityRepositoryImpl.java
index 4778a2261..f759e85b7 100644
--- a/storm-java21/src/main/java/st/orm/repository/impl/EntityRepositoryImpl.java
+++ b/storm-java21/src/main/java/st/orm/repository/impl/EntityRepositoryImpl.java
@@ -27,8 +27,6 @@
 import st.orm.Page;
 import st.orm.Pageable;
 import st.orm.Ref;
-import st.orm.Scrollable;
-import st.orm.Window;
 import st.orm.repository.EntityRepository;
 import st.orm.template.Model;
 import st.orm.template.ORMTemplate;
@@ -248,11 +246,6 @@ public Page<Ref<E>> pageRef(Pageable pageable) {
         return core.pageRef(pageable);
     }
 
-    @Override
-    public Window<E> scroll(Scrollable<E> scrollable) {
-        return select().scroll(scrollable);
-    }
-
     @Override
     public List<E> findAll() {
         return core.findAll();
diff --git a/storm-java21/src/main/java/st/orm/repository/impl/ProjectionRepositoryImpl.java b/storm-java21/src/main/java/st/orm/repository/impl/ProjectionRepositoryImpl.java
index b926bc0db..233b67fa1 100644
--- a/storm-java21/src/main/java/st/orm/repository/impl/ProjectionRepositoryImpl.java
+++ b/storm-java21/src/main/java/st/orm/repository/impl/ProjectionRepositoryImpl.java
@@ -27,8 +27,6 @@
 import st.orm.Pageable;
 import st.orm.Projection;
 import st.orm.Ref;
-import st.orm.Scrollable;
-import st.orm.Window;
 import st.orm.repository.ProjectionRepository;
 import st.orm.template.Model;
 import st.orm.template.ORMTemplate;
@@ -133,13 +131,6 @@ public Page<Ref<P>> pageRef(Pageable pageable) {
         return core.pageRef(pageable);
     }
 
-    // Window methods.
-
-    @Override
-    public Window<P> scroll(Scrollable<P> scrollable) {
-        return select().scroll(scrollable);
-    }
-
     @Override
     public Optional<P> findById(ID id) {
         return core.findById(id);
diff --git a/storm-kotlin-spring-boot-starter/src/main/kotlin/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.kt b/storm-kotlin-spring-boot-starter/src/main/kotlin/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.kt
index 5d2677858..3e97238f0 100644
--- a/storm-kotlin-spring-boot-starter/src/main/kotlin/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.kt
+++ b/storm-kotlin-spring-boot-starter/src/main/kotlin/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.kt
@@ -55,8 +55,6 @@ import javax.sql.DataSource
 @EnableConfigurationProperties(StormProperties::class)
 public open class StormAutoConfiguration {
 
-    private val logger = org.slf4j.LoggerFactory.getLogger(StormAutoConfiguration::class.java)
-
     /**
      * Creates an [ORMTemplate] bean using the provided [DataSource] and [StormProperties].
      *
diff --git a/storm-kotlin/src/main/java/st/orm/spi/ORMReflectionImpl.java b/storm-kotlin/src/main/java/st/orm/spi/ORMReflectionImpl.java
index 396471dad..61ce1b9b0 100644
--- a/storm-kotlin/src/main/java/st/orm/spi/ORMReflectionImpl.java
+++ b/storm-kotlin/src/main/java/st/orm/spi/ORMReflectionImpl.java
@@ -160,15 +160,6 @@ public Optional<RecordType> findRecordType(Class<?> type) {
         });
     }
 
-    private KProperty1<?, ?> findVarProperty(KClass<?> kClass) {
-        for (KProperty1<?, ?> prop : KClasses.getMemberProperties(kClass)) {
-            if (prop instanceof KMutableProperty1<?, ?>) {
-                return prop;
-            }
-        }
-        return null;
-    }
-
     private boolean isMutableProperty(Class<?> declaringClass, String name) {
         KClass<?> kClass = JvmClassMappingKt.getKotlinClass(declaringClass);
         for (KProperty1<?, ?> p : KClasses.getMemberProperties(kClass)) {
@@ -268,9 +259,6 @@ private Optional<Constructor<?>> findCanonicalConstructor(Class<?> type) {
                 return empty();
             }
             KClass<?> kClass = JvmClassMappingKt.getKotlinClass(type);
-            if (!kClass.isData()) {
-                return Optional.empty();
-            }
             @SuppressWarnings("unchecked")
             KFunction<?> primary = KClasses.getPrimaryConstructor((KClass<Object>) kClass);
             if (primary == null) {
diff --git a/storm-kotlin/src/main/kotlin/st/orm/repository/RepositoryLookup.kt b/storm-kotlin/src/main/kotlin/st/orm/repository/RepositoryLookup.kt
index 197cbe7ba..ccf0c218a 100644
--- a/storm-kotlin/src/main/kotlin/st/orm/repository/RepositoryLookup.kt
+++ b/storm-kotlin/src/main/kotlin/st/orm/repository/RepositoryLookup.kt
@@ -232,12 +232,7 @@ public inline fun <reified T : Data> RepositoryLookup.findAll(): List<T> = if (T
  *
  * @return list containing all records.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.findAllRef(): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data> RepositoryLookup.findAllRef(): List<Ref<T>> = selectRef<T>().resultList
 
 /**
  * Retrieves an optional record of type [T] based on a single field and its value.
@@ -249,12 +244,7 @@ public inline fun <reified T : Data> RepositoryLookup.findAllRef(): List<Ref<T>>
  * @param value the value to match against.
  * @return an optional record, or null if none found.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findBy(field: Metamodel<T, V>, value: V): T? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where((field as Metamodel<Entity<*>, V>) eq value).optionalResult as T?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where((field as Metamodel<Projection<*>, V>) eq value).optionalResult as T?
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findBy(field: Metamodel<T, V>, value: V): T? = select<T>().where(field eq value).optionalResult
 
 /**
  * Retrieves an optional record of type [T] based on a single field and its value.
@@ -266,12 +256,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findBy(field: Metamodel
  * @param value the value to match against.
  * @return an optional record, or null if none found.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findBy(field: Metamodel<T, V>, value: Ref<V>): T? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(field as Metamodel<Entity<*>, V>, value).optionalResult as T?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(field as Metamodel<Projection<*>, V>, value).optionalResult as T?
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findBy(field: Metamodel<T, V>, value: Ref<V>): T? = select<T>().where(field, value).optionalResult
 
 /**
  * Retrieves records of type [T] matching a single field and a single value.
@@ -283,12 +268,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findBy(field: Me
  * @param value the value to match against.
  * @return list of matching records.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamodel<T, V>, value: V): List<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where((field as Metamodel<Entity<*>, V>) eq value).resultList as List<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where((field as Metamodel<Projection<*>, V>) eq value).resultList as List<T>
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamodel<T, V>, value: V): List<T> = select<T>().where(field eq value).resultList
 
 /**
  * Retrieves records of type [T] matching a single field and a single value.
@@ -300,12 +280,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamo
  * @param value the value to match against.
  * @return list of matching records.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllBy(field: Metamodel<T, V>, value: Ref<V>): List<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(field as Metamodel<Entity<*>, V>, value).resultList as List<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(field as Metamodel<Projection<*>, V>, value).resultList as List<T>
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllBy(field: Metamodel<T, V>, value: Ref<V>): List<T> = select<T>().where(field, value).resultList
 
 /**
  * Retrieves records of type [T] matching a single field against multiple values.
@@ -317,12 +292,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllBy(field:
  * @param values Iterable of values to match against.
  * @return list of matching records.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamodel<T, V>, values: Iterable<V>): List<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where((field as Metamodel<Entity<*>, V>) inList values).resultList as List<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where((field as Metamodel<Projection<*>, V>) inList values).resultList as List<T>
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamodel<T, V>, values: Iterable<V>): List<T> = select<T>().where(field inList values).resultList
 
 /**
  * Retrieves records of type [T] matching a single field against multiple values.
@@ -334,12 +304,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findAllBy(field: Metamo
  * @param values Iterable of values to match against.
  * @return list of matching records.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllByRef(field: Metamodel<T, V>, values: Iterable<Ref<V>>): List<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().whereRef(field as Metamodel<Entity<*>, V>, values).resultList as List<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().whereRef(field as Metamodel<Projection<*>, V>, values).resultList as List<T>
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllByRef(field: Metamodel<T, V>, values: Iterable<Ref<V>>): List<T> = select<T>().whereRef(field, values).resultList
 
 /**
  * Retrieves exactly one record of type [T] based on a single field and its value.
@@ -353,12 +318,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllByRef(fie
  * @throws st.orm.NoResultException if there is no result.
  * @throws st.orm.NonUniqueResultException if more than one result.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.getBy(field: Metamodel<T, V>, value: V): T = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where((field as Metamodel<Entity<*>, V>) eq value).singleResult as T
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where((field as Metamodel<Projection<*>, V>) eq value).singleResult as T
-}
+public inline fun <reified T : Data, V> RepositoryLookup.getBy(field: Metamodel<T, V>, value: V): T = select<T>().where(field eq value).singleResult
 
 /**
  * Retrieves exactly one record of type [T] based on a single field and its value.
@@ -372,12 +332,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.getBy(field: Metamodel<
  * @throws st.orm.NoResultException if there is no result.
  * @throws st.orm.NonUniqueResultException if more than one result.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.getBy(field: Metamodel<T, V>, value: Ref<V>): T = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(field as Metamodel<Entity<*>, V>, value).singleResult as T
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(field as Metamodel<Projection<*>, V>, value).singleResult as T
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.getBy(field: Metamodel<T, V>, value: Ref<V>): T = select<T>().where(field, value).singleResult
 
 /**
  * Retrieves an optional entity of type [T] based on a single field and its value.
@@ -387,12 +342,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.getBy(field: Met
  * @param value the value to match against.
  * @return an optional entity, or null if none found.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findRefBy(field: Metamodel<T, V>, value: V): Ref<T>? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where((field as Metamodel<Entity<*>, V>) eq value).optionalResult as Ref<T>?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where((field as Metamodel<Projection<*>, V>) eq value).optionalResult as Ref<T>?
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findRefBy(field: Metamodel<T, V>, value: V): Ref<T>? = selectRef<T>().where(field eq value).optionalResult
 
 /**
  * Retrieves an optional entity of type [T] based on a single field and its value.
@@ -402,12 +352,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findRefBy(field: Metamo
  * @param value the value to match against.
  * @return an optional entity, or null if none found.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findRefBy(field: Metamodel<T, V>, value: Ref<V>): Ref<T>? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(field as Metamodel<Entity<*>, V>, value).optionalResult as Ref<T>?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(field as Metamodel<Projection<*>, V>, value).optionalResult as Ref<T>?
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findRefBy(field: Metamodel<T, V>, value: Ref<V>): Ref<T>? = selectRef<T>().where(field, value).optionalResult
 
 /**
  * Retrieves entities of type [T] matching a single field and a single value.
@@ -417,12 +362,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findRefBy(field:
  * @param value the value to match against.
  * @return list of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, value: V): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where((field as Metamodel<Entity<*>, V>) eq value).resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where((field as Metamodel<Projection<*>, V>) eq value).resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, value: V): List<Ref<T>> = selectRef<T>().where(field eq value).resultList
 
 /**
  * Retrieves entities of type [T] matching a single field and a single value.
@@ -432,12 +372,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Met
  * @param value the value to match against.
  * @return list of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, value: Ref<V>): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(field as Metamodel<Entity<*>, V>, value).resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(field as Metamodel<Projection<*>, V>, value).resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, value: Ref<V>): List<Ref<T>> = selectRef<T>().where(field, value).resultList
 
 /**
  * Retrieves entities of type [T] matching a single field against multiple values.
@@ -447,12 +382,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefBy(fie
  * @param values Iterable of values to match against.
  * @return list of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, values: Iterable<V>): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where((field as Metamodel<Entity<*>, V>) inList values).resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where((field as Metamodel<Projection<*>, V>) inList values).resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Metamodel<T, V>, values: Iterable<V>): List<Ref<T>> = selectRef<T>().where(field inList values).resultList
 
 /**
  * Retrieves entities of type [T] matching a single field against multiple values.
@@ -462,12 +392,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.findAllRefBy(field: Met
  * @param values Iterable of values to match against.
  * @return list of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefByRef(field: Metamodel<T, V>, values: Iterable<Ref<V>>): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().whereRef(field as Metamodel<Entity<*>, V>, values).resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().whereRef(field as Metamodel<Projection<*>, V>, values).resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefByRef(field: Metamodel<T, V>, values: Iterable<Ref<V>>): List<Ref<T>> = selectRef<T>().whereRef(field, values).resultList
 
 /**
  * Retrieves exactly one entity of type [T] based on a single field and its value.
@@ -479,12 +404,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.findAllRefByRef(
  * @throws st.orm.NoResultException if there is no result.
  * @throws st.orm.NonUniqueResultException if more than one result.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.getRefBy(field: Metamodel<T, V>, value: V): Ref<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where((field as Metamodel<Entity<*>, V>) eq value).singleResult as Ref<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where((field as Metamodel<Projection<*>, V>) eq value).singleResult as Ref<T>
-}
+public inline fun <reified T : Data, V> RepositoryLookup.getRefBy(field: Metamodel<T, V>, value: V): Ref<T> = selectRef<T>().where(field eq value).singleResult
 
 /**
  * Retrieves exactly one entity of type [T] based on a single field and its value.
@@ -496,12 +416,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.getRefBy(field: Metamod
  * @throws st.orm.NoResultException if there is no result.
  * @throws st.orm.NonUniqueResultException if more than one result.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.getRefBy(field: Metamodel<T, V>, value: Ref<V>): Ref<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(field as Metamodel<Entity<*>, V>, value).singleResult as Ref<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(field as Metamodel<Projection<*>, V>, value).singleResult as Ref<T>
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.getRefBy(field: Metamodel<T, V>, value: Ref<V>): Ref<T> = selectRef<T>().where(field, value).singleResult
 
 /**
  * Creates a query builder to select records of type [T].
@@ -510,12 +425,7 @@ public inline fun <reified T : Data, V : Data> RepositoryLookup.getRefBy(field:
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.findAll(predicate: PredicateBuilder<T, *, *>): List<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(predicate as PredicateBuilder<Entity<*>, *, *>).resultList as List<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(predicate as PredicateBuilder<Projection<*>, *, *>).resultList as List<T>
-}
+public inline fun <reified T : Data> RepositoryLookup.findAll(predicate: PredicateBuilder<T, *, *>): List<T> = select<T>().where(predicate).resultList
 
 /**
  * Creates a query builder to select records of type [T].
@@ -524,12 +434,7 @@ public inline fun <reified T : Data> RepositoryLookup.findAll(predicate: Predica
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.findAllRef(predicate: PredicateBuilder<T, *, *>): List<Ref<T>> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(predicate as PredicateBuilder<Entity<*>, *, *>).resultList as List<Ref<T>>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(predicate as PredicateBuilder<Projection<*>, *, *>).resultList as List<Ref<T>>
-}
+public inline fun <reified T : Data> RepositoryLookup.findAllRef(predicate: PredicateBuilder<T, *, *>): List<Ref<T>> = selectRef<T>().where(predicate).resultList
 
 /**
  * Creates a query builder to select records of type [T].
@@ -538,12 +443,7 @@ public inline fun <reified T : Data> RepositoryLookup.findAllRef(predicate: Pred
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.find(predicate: PredicateBuilder<T, *, *>): T? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(predicate as PredicateBuilder<Entity<*>, *, *>).optionalResult as T?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(predicate as PredicateBuilder<Projection<*>, *, *>).optionalResult as T?
-}
+public inline fun <reified T : Data> RepositoryLookup.find(predicate: PredicateBuilder<T, *, *>): T? = select<T>().where(predicate).optionalResult
 
 /**
  * Creates a query builder to select records of type [T].
@@ -552,12 +452,7 @@ public inline fun <reified T : Data> RepositoryLookup.find(predicate: PredicateB
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.findRef(predicate: PredicateBuilder<T, *, *>): Ref<T>? = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(predicate as PredicateBuilder<Entity<*>, *, *>).optionalResult as Ref<T>?
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(predicate as PredicateBuilder<Projection<*>, *, *>).optionalResult as Ref<T>?
-}
+public inline fun <reified T : Data> RepositoryLookup.findRef(predicate: PredicateBuilder<T, *, *>): Ref<T>? = selectRef<T>().where(predicate).optionalResult
 
 /**
  * Creates a query builder to select records of type [T].
@@ -566,12 +461,7 @@ public inline fun <reified T : Data> RepositoryLookup.findRef(predicate: Predica
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.get(predicate: PredicateBuilder<T, *, *>): T = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).select().where(predicate as PredicateBuilder<Entity<*>, *, *>).singleResult as T
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).select().where(predicate as PredicateBuilder<Projection<*>, *, *>).singleResult as T
-}
+public inline fun <reified T : Data> RepositoryLookup.get(predicate: PredicateBuilder<T, *, *>): T = select<T>().where(predicate).singleResult
 
 /**
  * Creates a query builder to select records of type [T].
@@ -580,12 +470,7 @@ public inline fun <reified T : Data> RepositoryLookup.get(predicate: PredicateBu
  *
  * @return A [QueryBuilder] for selecting records of type [T].
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.getRef(predicate: PredicateBuilder<T, *, *>): Ref<T> = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectRef().where(predicate as PredicateBuilder<Entity<*>, *, *>).singleResult as Ref<T>
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef().where(predicate as PredicateBuilder<Projection<*>, *, *>).singleResult as Ref<T>
-}
+public inline fun <reified T : Data> RepositoryLookup.getRef(predicate: PredicateBuilder<T, *, *>): Ref<T> = selectRef<T>().where(predicate).singleResult
 
 /**
  * Creates a query builder to select records of type [T].
@@ -612,7 +497,6 @@ public inline fun <reified T : Data> RepositoryLookup.select(): QueryBuilder<T,
  *
  * @return A [QueryBuilder] with the predicate applied.
  */
-@Suppress("UNCHECKED_CAST")
 public inline fun <reified T : Data> RepositoryLookup.select(
     predicate: PredicateBuilder<T, *, *>,
 ): QueryBuilder<T, T, *> = select<T>().where(predicate)
@@ -629,6 +513,21 @@ public inline fun <reified T : Data> RepositoryLookup.selectRef(): QueryBuilder<
     (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectRef() as QueryBuilder<T, Ref<T>, *>
 }
 
+/**
+ * Creates a query builder to count records of type [T]; the counting counterpart of [select].
+ *
+ * [T] must be either an Entity or Projection type.
+ *
+ * @return A [QueryBuilder] counting records of type [T].
+ */
+@PublishedApi
+@Suppress("UNCHECKED_CAST")
+internal inline fun <reified T : Data> RepositoryLookup.selectCount(): QueryBuilder<T, Long, *> = if (T::class.isSubclassOf(Entity::class)) {
+    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount() as QueryBuilder<T, Long, *>
+} else {
+    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount() as QueryBuilder<T, Long, *>
+}
+
 /**
  * Counts entities of type [T] matching the specified field and value.
  *
@@ -636,12 +535,7 @@ public inline fun <reified T : Data> RepositoryLookup.selectRef(): QueryBuilder<
  * @param value the value to match against.
  * @return the count of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.countBy(field: Metamodel<T, V>, value: V): Long = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where((field as Metamodel<Entity<*>, V>) eq value).singleResult
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where((field as Metamodel<Projection<*>, V>) eq value).singleResult
-}
+public inline fun <reified T : Data, V> RepositoryLookup.countBy(field: Metamodel<T, V>, value: V): Long = selectCount<T>().where(field eq value).singleResult
 
 /**
  * Counts entities of type [T] matching the specified field and referenced value.
@@ -650,12 +544,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.countBy(field: Metamode
  * @param value the referenced value to match against.
  * @return the count of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.countBy(field: Metamodel<T, V>, value: Ref<V>): Long = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where(field as Metamodel<Entity<*>, V>, value).singleResult
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where(field as Metamodel<Projection<*>, V>, value).singleResult
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.countBy(field: Metamodel<T, V>, value: Ref<V>): Long = selectCount<T>().where(field, value).singleResult
 
 /**
  * Counts entities of type [T] matching the specified predicate.
@@ -675,12 +564,7 @@ public inline fun <reified T : Data> RepositoryLookup.countAll(): Long = if (T::
  * @param predicate Lambda to build the WHERE clause.
  * @return the count of matching entities.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.count(predicate: PredicateBuilder<T, *, *>): Long = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where(predicate as PredicateBuilder<Entity<*>, *, *>).singleResult
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where(predicate as PredicateBuilder<Projection<*>, *, *>).singleResult
-}
+public inline fun <reified T : Data> RepositoryLookup.count(predicate: PredicateBuilder<T, *, *>): Long = selectCount<T>().where(predicate).singleResult
 
 /**
  * Checks if entities of type [T] matching the specified field and value exists.
@@ -689,12 +573,7 @@ public inline fun <reified T : Data> RepositoryLookup.count(predicate: Predicate
  * @param value the value to match against.
  * @return true if any matching entities exist, false otherwise.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V> RepositoryLookup.existsBy(field: Metamodel<T, V>, value: V): Boolean = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where((field as Metamodel<Entity<*>, V>) eq value).singleResult > 0
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where((field as Metamodel<Projection<*>, V>) eq value).singleResult > 0
-}
+public inline fun <reified T : Data, V> RepositoryLookup.existsBy(field: Metamodel<T, V>, value: V): Boolean = selectCount<T>().where(field eq value).singleResult > 0
 
 /**
  * Checks if entities of type [T] matching the specified field and referenced value exists.
@@ -703,12 +582,7 @@ public inline fun <reified T : Data, V> RepositoryLookup.existsBy(field: Metamod
  * @param value the referenced value to match against.
  * @return true if any matching entities exist, false otherwise.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data, V : Data> RepositoryLookup.existsBy(field: Metamodel<T, V>, value: Ref<V>): Boolean = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where(field as Metamodel<Entity<*>, V>, value).singleResult > 0
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where(field as Metamodel<Projection<*>, V>, value).singleResult > 0
-}
+public inline fun <reified T : Data, V : Data> RepositoryLookup.existsBy(field: Metamodel<T, V>, value: Ref<V>): Boolean = selectCount<T>().where(field, value).singleResult > 0
 
 /**
  * Checks if entities of type [T] matching the specified predicate exists.
@@ -728,12 +602,7 @@ public inline fun <reified T : Data> RepositoryLookup.exists(): Boolean = if (T:
  * @param predicate Lambda to build the WHERE clause.
  * @return true if any matching entities exist, false otherwise.
  */
-@Suppress("UNCHECKED_CAST")
-public inline fun <reified T : Data> RepositoryLookup.exists(predicate: PredicateBuilder<T, *, *>): Boolean = if (T::class.isSubclassOf(Entity::class)) {
-    (entity(T::class as KClass<Entity<Any>>) as EntityRepository<Entity<*>, *>).selectCount().where(predicate as PredicateBuilder<Entity<*>, *, *>).singleResult > 0
-} else {
-    (projection(T::class as KClass<Projection<Any>>) as ProjectionRepository<Projection<*>, *>).selectCount().where(predicate as PredicateBuilder<Projection<*>, *, *>).singleResult > 0
-}
+public inline fun <reified T : Data> RepositoryLookup.exists(predicate: PredicateBuilder<T, *, *>): Boolean = selectCount<T>().where(predicate).singleResult > 0
 
 /**
  * Inserts an entity of type [T] into the repository.
diff --git a/storm-kotlin/src/main/kotlin/st/orm/template/QueryBuilder.kt b/storm-kotlin/src/main/kotlin/st/orm/template/QueryBuilder.kt
index 45ce74b14..70eab1eab 100644
--- a/storm-kotlin/src/main/kotlin/st/orm/template/QueryBuilder.kt
+++ b/storm-kotlin/src/main/kotlin/st/orm/template/QueryBuilder.kt
@@ -20,6 +20,7 @@ import kotlinx.coroutines.stream.consumeAsFlow
 import st.orm.*
 import st.orm.Operator.*
 import st.orm.ResolveScope.CASCADE
+import st.orm.core.template.impl.Elements
 import st.orm.core.template.impl.Elements.Clause.GROUP_BY
 import st.orm.core.template.impl.Elements.Clause.ORDER_BY_ASCENDING
 import st.orm.core.template.impl.Elements.Clause.ORDER_BY_DESCENDING
@@ -665,18 +666,29 @@ public abstract class QueryBuilder<T : Data, R, ID> {
         // We can safely invoke groupByAny as the underlying logic is identical. The main purpose of having these
         // separate methods is to provide (more) type safety when using metamodels that are guaranteed to be present in
         // the table graph.
+        return groupBy(columnList(path, GROUP_BY, "GROUP BY"))
+    }
+
+    /**
+     * Renders the paths as a comma-separated column list for the given clause.
+     */
+    private fun columnList(
+        path: Array<out Navigable<out T, *>>,
+        clause: Elements.Clause,
+        clauseName: String,
+    ): TemplateString {
         if (path.isEmpty()) {
-            throw PersistenceException("At least one path must be provided for GROUP BY clause.")
+            throw PersistenceException("At least one path must be provided for $clauseName clause.")
         }
         val templates = buildList {
             path.forEachIndexed { index, navigable ->
-                add(wrap(Columns(listOf(navigable.asMetamodel()), CASCADE, GROUP_BY)))
+                add(wrap(Columns(listOf(navigable.asMetamodel()), CASCADE, clause)))
                 if (index < path.lastIndex) {
                     add(raw(", "))
                 }
             }
         }
-        return groupBy(combine(*templates.toTypedArray()))
+        return combine(*templates.toTypedArray())
     }
 
     /**
@@ -801,20 +813,7 @@ public abstract class QueryBuilder<T : Data, R, ID> {
      * @return the query builder.
      * @since 1.2
      */
-    public fun orderBy(vararg path: Navigable<out T, *>): QueryBuilder<T, R, ID> {
-        if (path.isEmpty()) {
-            throw PersistenceException("At least one path must be provided for ORDER BY clause.")
-        }
-        val templates = buildList {
-            path.forEachIndexed { index, navigable ->
-                add(wrap(Columns(listOf(navigable.asMetamodel()), CASCADE, ORDER_BY_ASCENDING)))
-                if (index < path.lastIndex) {
-                    add(raw(", "))
-                }
-            }
-        }
-        return orderBy(combine(*templates.toTypedArray()))
-    }
+    public fun orderBy(vararg path: Navigable<out T, *>): QueryBuilder<T, R, ID> = orderBy(columnList(path, ORDER_BY_ASCENDING, "ORDER BY"))
 
     /**
      * Adds an ORDER BY clause to the query for the field at the specified path in the table graph. The results are
@@ -834,20 +833,7 @@ public abstract class QueryBuilder<T : Data, R, ID> {
      * @return the query builder.
      * @since 1.9
      */
-    public fun orderByDescending(vararg path: Navigable<out T, *>): QueryBuilder<T, R, ID> {
-        if (path.isEmpty()) {
-            throw PersistenceException("At least one path must be provided for ORDER BY clause.")
-        }
-        val templates = buildList {
-            path.forEachIndexed { index, navigable ->
-                add(wrap(Columns(listOf(navigable.asMetamodel()), CASCADE, ORDER_BY_DESCENDING)))
-                if (index < path.size - 1) {
-                    add(raw(", "))
-                }
-            }
-        }
-        return orderBy(combine(*templates.toTypedArray()))
-    }
+    public fun orderByDescending(vararg path: Navigable<out T, *>): QueryBuilder<T, R, ID> = orderBy(columnList(path, ORDER_BY_DESCENDING, "ORDER BY"))
 
     /**
      * Adds an ORDER BY clause to the query using a string template. The results are sorted in descending order.
diff --git a/storm-kotlin/src/main/kotlin/st/orm/template/impl/ORMTemplateImpl.kt b/storm-kotlin/src/main/kotlin/st/orm/template/impl/ORMTemplateImpl.kt
index d6f6d979f..f8a4ae294 100644
--- a/storm-kotlin/src/main/kotlin/st/orm/template/impl/ORMTemplateImpl.kt
+++ b/storm-kotlin/src/main/kotlin/st/orm/template/impl/ORMTemplateImpl.kt
@@ -137,52 +137,37 @@ internal class ORMTemplateImpl(private val core: st.orm.core.template.ORMTemplat
         } as R
     }
 
-    private fun createEntityRepository(type: KClass<*>): EntityRepository<*, *>? {
-        if (!EntityRepository::class.java.isAssignableFrom(type.java)) return null
-        var entityClass: Class<*>? = null
-        for (iface in type.java.genericInterfaces) {
-            if (iface is ParameterizedType &&
-                (iface.rawType as? Class<*>)?.let {
-                    EntityRepository::class.java.isAssignableFrom(it)
-                } == true
-            ) {
-                val arg = iface.actualTypeArguments[0]
-                if (arg is Class<*>) {
-                    entityClass = arg
-                    break
-                }
-            }
-        }
-        requireNotNull(entityClass) {
-            "Could not determine entity class for repository: ${type.simpleName}."
-        }
-        // Use Java reflection to invoke the generic 'entity' method at runtime.
-        val method = this.javaClass.getMethod("entity", KClass::class.java)
-        return method.invoke(this, entityClass.kotlin) as EntityRepository<*, *>
-    }
+    private fun createEntityRepository(type: KClass<*>): EntityRepository<*, *>? = createRepositoryFor(type, EntityRepository::class.java, "entity") as EntityRepository<*, *>?
+
+    private fun createProjectionRepository(type: KClass<*>): ProjectionRepository<*, *>? = createRepositoryFor(type, ProjectionRepository::class.java, "projection") as ProjectionRepository<*, *>?
 
-    private fun createProjectionRepository(type: KClass<*>): ProjectionRepository<*, *>? {
-        if (!ProjectionRepository::class.java.isAssignableFrom(type.java)) return null
-        var projectionClass: Class<*>? = null
+    /**
+     * Creates the backing repository for a proxied repository interface: resolves the data type from the
+     * repository interface's type argument and invokes the given factory method ('entity' or 'projection')
+     * with it, or returns null when the interface does not extend the given repository type.
+     */
+    private fun createRepositoryFor(type: KClass<*>, repositoryInterface: Class<*>, factoryMethod: String): Any? {
+        if (!repositoryInterface.isAssignableFrom(type.java)) return null
+        var dataClass: Class<*>? = null
         for (iface in type.java.genericInterfaces) {
             if (iface is ParameterizedType &&
                 (iface.rawType as? Class<*>)?.let {
-                    ProjectionRepository::class.java.isAssignableFrom(it)
+                    repositoryInterface.isAssignableFrom(it)
                 } == true
             ) {
                 val arg = iface.actualTypeArguments[0]
                 if (arg is Class<*>) {
-                    projectionClass = arg
+                    dataClass = arg
                     break
                 }
             }
         }
-        requireNotNull(projectionClass) {
-            "Could not determine projection class for repository: ${type.simpleName}."
+        requireNotNull(dataClass) {
+            "Could not determine $factoryMethod class for repository: ${type.simpleName}."
         }
-        // Use Java reflection to invoke the generic 'projection' method at runtime.
-        val method = this.javaClass.getMethod("projection", KClass::class.java)
-        return method.invoke(this, projectionClass.kotlin) as ProjectionRepository<*, *>
+        // Use Java reflection to invoke the generic factory method at runtime.
+        val method = this.javaClass.getMethod(factoryMethod, KClass::class.java)
+        return method.invoke(this, dataClass.kotlin)
     }
 
     private fun createRepository(): Repository = object : Repository {
diff --git a/storm-kotlin/src/main/kotlin/st/orm/template/impl/PredicateBuilderFactory.kt b/storm-kotlin/src/main/kotlin/st/orm/template/impl/PredicateBuilderFactory.kt
index 231b72596..73c09700f 100644
--- a/storm-kotlin/src/main/kotlin/st/orm/template/impl/PredicateBuilderFactory.kt
+++ b/storm-kotlin/src/main/kotlin/st/orm/template/impl/PredicateBuilderFactory.kt
@@ -57,42 +57,6 @@ internal fun <T : Data, R, V : Data> createRef(
     o: Iterable<Ref<V>>,
 ): PredicateBuilder<T, R, *> = PredicateBuilderImpl(PredicateBuilderFactory.createRef(path, operator, o))
 
-/**
- * Creates a new instance of [PredicateBuilder] for the specified path, operator, and values with an ID.
- *
- * @param path the metamodel path representing the field to be queried
- * @param operator the operator to be used in the predicate
- * @param o the values to be used in the predicate
- * @param <T> the type of the record
- * @param <R> the type of the result
- * @param <ID> the type of the ID
- * @param <V> the type of the values
- * @return a new instance of [PredicateBuilder]
- */
-internal fun <T : Data, R, ID, V> createWithId(
-    path: Metamodel<*, V>,
-    operator: Operator,
-    o: Iterable<V>,
-): PredicateBuilder<T, R, ID> = PredicateBuilderImpl(PredicateBuilderFactory.createWithId(path, operator, o))
-
-/**
- * Creates a new instance of [PredicateBuilder] for the specified path, operator, and values with an ID.
- *
- * @param path the metamodel path representing the field to be queried
- * @param operator the operator to be used in the predicate
- * @param o the values to be used in the predicate
- * @param <T> the type of the record
- * @param <R> the type of the result
- * @param <ID> the type of the ID
- * @param <V> the type of the values
- * @return a new instance of [PredicateBuilder]
- */
-internal fun <T : Data, R, ID, V : Data> createRefWithId(
-    path: Metamodel<*, V>,
-    operator: Operator,
-    o: Iterable<Ref<V>>,
-): PredicateBuilder<T, R, ID> = PredicateBuilderImpl(PredicateBuilderFactory.createRefWithId(path, operator, o))
-
 /**
  * Combines two predicates using an AND condition, rooting the result at the operands' least common root.
  *
diff --git a/storm-kotlin/src/main/kotlin/st/orm/template/impl/TransactionCallbacks.kt b/storm-kotlin/src/main/kotlin/st/orm/template/impl/TransactionCallbacks.kt
index da356919d..08705bb8d 100644
--- a/storm-kotlin/src/main/kotlin/st/orm/template/impl/TransactionCallbacks.kt
+++ b/storm-kotlin/src/main/kotlin/st/orm/template/impl/TransactionCallbacks.kt
@@ -25,7 +25,7 @@ import java.util.function.Consumer
  *
  * Callbacks registered via [addOnCommit], [addOnRollback] and [addOnCompletion] are stored in a single list, so
  * they run in registration order regardless of which kind they are; the ones that do not apply to the outcome are
- * skipped. When [fireCommit] or [fireRollback] is called, the applicable callbacks are executed sequentially in
+ * skipped. When the transaction settles, the applicable callbacks are executed sequentially in
  * the enclosing coroutine context. If any callback throws, remaining callbacks still execute and the failures are
  * reported as a [TransactionCallbackException] whose cause is the first one, with subsequent ones added to it as
  * suppressed.
@@ -95,15 +95,7 @@ internal class TransactionCallbacks : st.orm.core.spi.TransactionCallbacks {
                 return
             }
         }
-        if (committed) fireCommit() else fireRollback()
-    }
-
-    suspend fun fireCommit() {
-        fire(true)
-    }
-
-    suspend fun fireRollback() {
-        fire(false)
+        fire(committed)
     }
 
     private suspend fun fire(committed: Boolean) {
diff --git a/storm-kotlin/src/test/kotlin/st/orm/template/TemplatesTest.kt b/storm-kotlin/src/test/kotlin/st/orm/template/TemplatesTest.kt
index b7ba09147..2b18dfd96 100644
--- a/storm-kotlin/src/test/kotlin/st/orm/template/TemplatesTest.kt
+++ b/storm-kotlin/src/test/kotlin/st/orm/template/TemplatesTest.kt
@@ -614,18 +614,6 @@ internal open class TemplatesTest(
         predicate.shouldBeInstanceOf<PredicateBuilder<*, *, *>>()
     }
 
-    @Test
-    fun `createWithId predicate builder should return PredicateBuilder`() {
-        val metamodel = Metamodel.of<City, Int>(City::class.java, "id")
-        val predicate = st.orm.template.impl.createWithId<City, City, Int, Int>(
-            metamodel,
-            Operator.IN,
-            listOf(1, 2, 3),
-        )
-        predicate.shouldNotBe(null)
-        predicate.shouldBeInstanceOf<PredicateBuilder<*, *, *>>()
-    }
-
     @Test
     fun `predicate builder or composition should return PredicateBuilder`() {
         val metamodel = Metamodel.of<City, Int>(City::class.java, "id")
diff --git a/storm-ktor/src/main/kotlin/st/orm/ktor/Storm.kt b/storm-ktor/src/main/kotlin/st/orm/ktor/Storm.kt
index dcd53c6df..968277fb2 100644
--- a/storm-ktor/src/main/kotlin/st/orm/ktor/Storm.kt
+++ b/storm-ktor/src/main/kotlin/st/orm/ktor/Storm.kt
@@ -272,12 +272,13 @@ public val Storm: ApplicationPlugin<StormPluginConfig> = createApplicationPlugin
 
     // The packages declared by the named databases partition validation: each database validates only the entity
     // and projection types under its packages, and the primary validates everything else.
+    val rootSchemaMode = pluginConfig.schemaValidation
+        ?: application.environment.config.propertyOrNull("storm.validation.schemaMode")?.getString()
+        ?: application.environment.config.propertyOrNull("storm.validation.schema_mode")?.getString()
+        ?: "fail"
     application.runSchemaValidation(
         template = ormTemplate,
-        configuredMode = pluginConfig.schemaValidation
-            ?: application.environment.config.propertyOrNull("storm.validation.schemaMode")?.getString()
-            ?: application.environment.config.propertyOrNull("storm.validation.schema_mode")?.getString()
-            ?: "fail",
+        configuredMode = rootSchemaMode,
         property = "storm.validation.schemaMode",
         description = "primary database",
     ) { type -> claimedPackages.keys.none { type.java.name.startsWith("$it.") } }
@@ -290,10 +291,7 @@ public val Storm: ApplicationPlugin<StormPluginConfig> = createApplicationPlugin
             configuredMode = databaseConfig.schemaValidation
                 ?: application.environment.config.propertyOrNull("storm.databases.$name.validation.schemaMode")?.getString()
                 ?: application.environment.config.propertyOrNull("storm.databases.$name.validation.schema_mode")?.getString()
-                ?: pluginConfig.schemaValidation
-                ?: application.environment.config.propertyOrNull("storm.validation.schemaMode")?.getString()
-                ?: application.environment.config.propertyOrNull("storm.validation.schema_mode")?.getString()
-                ?: "fail",
+                ?: rootSchemaMode,
             property = "storm.databases.$name.validation.schemaMode",
             description = "database '$name'",
         ) { type -> databaseConfig.repositoryPackages.any { type.java.name.startsWith("$it.") } }
diff --git a/storm-mariadb/pom.xml b/storm-mariadb/pom.xml
index a8460380b..b0c8fd267 100644
--- a/storm-mariadb/pom.xml
+++ b/storm-mariadb/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.mariadb.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -107,6 +107,12 @@
             <scope>compile</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-mariadb/src/main/java/module-info.java b/storm-mariadb/src/main/java/module-info.java
index e8d691f74..19201f131 100644
--- a/storm-mariadb/src/main/java/module-info.java
+++ b/storm-mariadb/src/main/java/module-info.java
@@ -4,7 +4,6 @@
     requires storm.core;
     requires storm.mysql;
     requires static org.jspecify;
-    requires org.jetbrains.annotations;
     provides st.orm.core.spi.EntityRepositoryProvider with st.orm.spi.mariadb.MariaDBEntityRepositoryProviderImpl;
     provides st.orm.core.spi.SqlDialectProvider with st.orm.spi.mariadb.MariaDBSqlDialectProviderImpl;
 }
diff --git a/storm-mariadb/src/main/java/st/orm/spi/mariadb/MariaDBEntityRepositoryImpl.java b/storm-mariadb/src/main/java/st/orm/spi/mariadb/MariaDBEntityRepositoryImpl.java
index 4d6aef7b3..1c5db41c6 100644
--- a/storm-mariadb/src/main/java/st/orm/spi/mariadb/MariaDBEntityRepositoryImpl.java
+++ b/storm-mariadb/src/main/java/st/orm/spi/mariadb/MariaDBEntityRepositoryImpl.java
@@ -16,23 +16,16 @@
 package st.orm.spi.mariadb;
 
 import static st.orm.GenerationStrategy.SEQUENCE;
-import static st.orm.core.repository.impl.StreamSupport.partitioned;
 import static st.orm.core.template.SqlInterceptor.intercept;
 import static st.orm.core.template.TemplateString.raw;
 import static st.orm.core.template.impl.StringTemplates.flatten;
 
-import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import st.orm.Entity;
-import st.orm.Metamodel;
 import st.orm.core.repository.EntityRepository;
 import st.orm.core.template.Model;
 import st.orm.core.template.ORMTemplate;
-import st.orm.core.template.PreparedQuery;
 import st.orm.core.template.Query;
 import st.orm.core.template.TemplateString;
 import st.orm.spi.mysql.MySQLEntityRepositoryImpl;
@@ -52,19 +45,7 @@ public ID insertAndFetchId(E entity) {
         if (generationStrategy != SEQUENCE) {
             return super.insertAndFetchId(entity);
         }
-        entity = fireBeforeInsert(entity);
-        validateInsert(entity);
-        assert primaryKeyColumns.size() == 1;
-        var primaryKeyColumn = primaryKeyColumns.getFirst();
-        String pkName = primaryKeyColumn.qualifiedName(ormTemplate.dialect());
-        try (var query = ormTemplate.query(TemplateString.raw("""
-                INSERT INTO \0
-                VALUES \0
-                RETURNING %s""".formatted(pkName), model.type(), entity)).managed().prepare()) {
-            ID id = query.getSingleResult(model.primaryKeyType());
-            fireAfterInsert(entity, id);
-            return id;
-        }
+        return insertAndFetchIdReturning(entity);
     }
 
     /**
@@ -123,75 +104,31 @@ protected ID doUpsertAndFetchId(E entity) {
         });
     }
 
-    // Partition keys for the SEQUENCE-specific upsertAndFetchIds.
-    private sealed interface SeqPartitionKey {}
-    private static final class SeqNoOpKey implements SeqPartitionKey {
-        private static final SeqNoOpKey INSTANCE = new SeqNoOpKey();
-    }
-    private static final class SeqUpsertKey implements SeqPartitionKey {
-        private static final SeqUpsertKey INSTANCE = new SeqUpsertKey();
-    }
-    private record SeqUpdateKey(Set<Metamodel<?, ?>> fields) implements SeqPartitionKey {
-        SeqUpdateKey() {
-            this(Set.of());
-        }
-    }
-
     @Override
     public List<ID> upsertAndFetchIds(Iterable<E> entities) {
         if (generationStrategy != SEQUENCE) {
             return super.upsertAndFetchIds(entities);
         }
         // SEQUENCE path: use a single query with RETURNING clause instead of batched prepared statements.
-        Map<Set<Metamodel<?, ?>>, PreparedQuery> updateQueries = new HashMap<>();
-        try {
-            var result = new ArrayList<ID>();
-            var entityCache = entityCache();
-            partitioned(toStream(entities), defaultBatchSize, entity -> {
-                if (isUpsertUpdate(entity)) {
-                    var dirty = getDirty(entity, entityCache.orElse(null));
-                    if (dirty.isEmpty()) {
-                        return SeqNoOpKey.INSTANCE;
-                    }
-                    return new SeqUpdateKey(dirty.get());
+        return upsertAndFetchIdsPartitioned(entities, (chunk, entityCache) -> {
+            List<E> batch = hasEntityCallbacks()
+                    ? chunk.stream().map(this::fireBeforeUpsert).toList()
+                    : chunk;
+            entityCache.ifPresent(cache -> {
+                if (batch.stream().anyMatch(e -> model.isDefaultPrimaryKey(e.id()))) {
+                    // MySQL/MariaDB can update a record with the same unique key so we need to clear the
+                    // cache as we cannot predict which record is updated.
+                    cache.clear();
                 } else {
-                    return SeqUpsertKey.INSTANCE;
-                }
-            }, getMaxShapes(), new SeqUpdateKey()).forEach(partition -> {
-                switch (partition.key()) {
-                    case SeqNoOpKey ignore -> result.addAll(partition.chunk().stream().map(E::id).toList());
-                    case SeqUpsertKey ignore -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpsert).toList()
-                                : partition.chunk();
-                        entityCache.ifPresent(cache -> {
-                            if (batch.stream().anyMatch(e -> model.isDefaultPrimaryKey(e.id()))) {
-                                // MySQL/MariaDB can update a record with the same unique key so we need to clear the
-                                // cache as we cannot predict which record is updated.
-                                cache.clear();
-                            } else {
-                                batch.forEach(e -> cache.remove(e.id()));
-                            }
-                        });
-                        result.addAll(getUpsertQuery(batch).getResultList(model.primaryKeyType()));
-                        if (hasEntityCallbacks()) {
-                            batch.forEach(this::fireAfterUpsert);
-                        }
-                    }
-                    case SeqUpdateKey u -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpdate).toList()
-                                : partition.chunk();
-                        result.addAll(updateAndFetchIds(batch,
-                                updateQueries.computeIfAbsent(u.fields(), this::prepareUpdateQuery),
-                                entityCache.orElse(null)));
-                    }
+                    batch.forEach(e -> cache.remove(e.id()));
                 }
             });
-            return result;
-        } finally {
-            closeQuietly(updateQueries.values().stream());
-        }
+            List<ID> ids = getUpsertQuery(batch).getResultList(model.primaryKeyType());
+            if (hasEntityCallbacks()) {
+                batch.forEach(this::fireAfterUpsert);
+            }
+            return ids;
+        });
     }
 
     private Query getUpsertQuery(Iterable<E> entities) {
diff --git a/storm-mariadb/src/test/java/st/orm/spi/mariadb/testsupport/TestSpringConnectionProvider.java b/storm-mariadb/src/test/java/st/orm/spi/mariadb/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index 82e4e7e60..000000000
--- a/storm-mariadb/src/test/java/st/orm/spi/mariadb/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.mariadb.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-mariadb/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-mariadb/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index 95aca5c0f..b51953f70 100644
--- a/storm-mariadb/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-mariadb/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.mariadb.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-metamodel-ksp/src/main/kotlin/st/orm/metamodel/MetamodelProcessor.kt b/storm-metamodel-ksp/src/main/kotlin/st/orm/metamodel/MetamodelProcessor.kt
index 81e116ca8..6101c8be5 100644
--- a/storm-metamodel-ksp/src/main/kotlin/st/orm/metamodel/MetamodelProcessor.kt
+++ b/storm-metamodel-ksp/src/main/kotlin/st/orm/metamodel/MetamodelProcessor.kt
@@ -368,6 +368,16 @@ class MetamodelProcessor(
     }
 
     private fun renderKotlinBaseName(qualifiedName: String, currentPackage: String): String = when (qualifiedName) {
+        "kotlin.Any" -> "Any"
+        else -> renderResolvedKotlinName(qualifiedName, currentPackage)
+    }
+
+    /**
+     * Renders the Kotlin name of a resolved declaration for the generated source: primitive-mapped names stay
+     * simple, a name in the current package drops the package, and everything else stays fully qualified. The
+     * `kotlin.Any` mapping is deliberately absent; the resolved-field call sites render it qualified.
+     */
+    private fun renderResolvedKotlinName(qualifiedName: String, currentPackage: String): String = when (qualifiedName) {
         "kotlin.String", "java.lang.String" -> "String"
         "kotlin.Int", "java.lang.Integer" -> "Int"
         "kotlin.Long", "java.lang.Long" -> "Long"
@@ -377,7 +387,7 @@ class MetamodelProcessor(
         "kotlin.Double", "java.lang.Double" -> "Double"
         "kotlin.Float", "java.lang.Float" -> "Float"
         "kotlin.Char", "java.lang.Character" -> "Char"
-        "java.lang.Object", "kotlin.Any" -> "Any"
+        "java.lang.Object" -> "Any"
         else -> {
             if (qualifiedName.startsWith(currentPackage) && currentPackage.isNotEmpty()) {
                 val simpleName = qualifiedName.substring(currentPackage.length + 1)
@@ -403,26 +413,7 @@ class MetamodelProcessor(
             val decl = resolvedType.declaration
             val qualifiedName = decl.qualifiedName?.asString() ?: return "Any"
 
-            val baseName = when (qualifiedName) {
-                "kotlin.String", "java.lang.String" -> "String"
-                "kotlin.Int", "java.lang.Integer" -> "Int"
-                "kotlin.Long", "java.lang.Long" -> "Long"
-                "kotlin.Short", "java.lang.Short" -> "Short"
-                "kotlin.Byte", "java.lang.Byte" -> "Byte"
-                "kotlin.Boolean", "java.lang.Boolean" -> "Boolean"
-                "kotlin.Double", "java.lang.Double" -> "Double"
-                "kotlin.Float", "java.lang.Float" -> "Float"
-                "kotlin.Char", "java.lang.Character" -> "Char"
-                "java.lang.Object" -> "Any"
-                else -> {
-                    if (qualifiedName.startsWith(currentPackage) && currentPackage.isNotEmpty()) {
-                        val simpleName = qualifiedName.substring(currentPackage.length + 1)
-                        if (!simpleName.contains(".")) simpleName else qualifiedName
-                    } else {
-                        qualifiedName
-                    }
-                }
-            }
+            val baseName = renderResolvedKotlinName(qualifiedName, currentPackage)
             val typeArguments = resolvedType.arguments
             if (typeArguments.isNotEmpty() && typeArguments.all { it.variance != Variance.STAR }) {
                 val wildcards = typeArguments.joinToString(", ") { "*" }
@@ -448,26 +439,10 @@ class MetamodelProcessor(
         fun render(type: KSType): String {
             val decl = type.declaration
             val qualifiedName = decl.qualifiedName?.asString() ?: decl.simpleName.asString()
-            val baseName = when (qualifiedName) {
-                "st.orm.Ref" -> "st.orm.Ref"
-                "kotlin.String", "java.lang.String" -> "String"
-                "kotlin.Int", "java.lang.Integer" -> "Int"
-                "kotlin.Long", "java.lang.Long" -> "Long"
-                "kotlin.Short", "java.lang.Short" -> "Short"
-                "kotlin.Byte", "java.lang.Byte" -> "Byte"
-                "kotlin.Boolean", "java.lang.Boolean" -> "Boolean"
-                "kotlin.Double", "java.lang.Double" -> "Double"
-                "kotlin.Float", "java.lang.Float" -> "Float"
-                "kotlin.Char", "java.lang.Character" -> "Char"
-                "java.lang.Object" -> "Any"
-                else -> {
-                    if (qualifiedName.startsWith(currentPackage) && currentPackage.isNotEmpty()) {
-                        val simpleName = qualifiedName.substring(currentPackage.length + 1)
-                        if (!simpleName.contains(".")) simpleName else qualifiedName
-                    } else {
-                        qualifiedName
-                    }
-                }
+            val baseName = if (qualifiedName == "st.orm.Ref") {
+                "st.orm.Ref"
+            } else {
+                renderResolvedKotlinName(qualifiedName, currentPackage)
             }
             val args = type.arguments
             val typeArgs = if (args.isNotEmpty()) {
@@ -741,67 +716,75 @@ class MetamodelProcessor(
 
     private fun ensureNullable(typeName: String): String = if (typeName.endsWith("?")) typeName else "$typeName?"
 
+    /**
+     * Renders the comparison for a primitive-typed value: floats and doubles compare by bit pattern so NaN
+     * equals NaN, the other primitives by value; the null-safe form reads through nullable receivers.
+     */
+    private fun primitiveEq(left: String, right: String, pk: PrimitiveKind, nullSafe: Boolean): String = when (pk) {
+        PrimitiveKind.FLOAT,
+        PrimitiveKind.DOUBLE,
+        -> if (nullSafe) "($left)?.toBits() == ($right)?.toBits()" else "($left).toBits() == ($right).toBits()"
+        PrimitiveKind.BOOLEAN,
+        PrimitiveKind.BYTE,
+        PrimitiveKind.SHORT,
+        PrimitiveKind.INT,
+        PrimitiveKind.LONG,
+        PrimitiveKind.CHAR,
+        -> "$left == $right"
+    }
+
     private fun sameExpr(left: String, right: String, typeRef: KSTypeReference, forceNullableChain: Boolean): String {
         val pk = primitiveKind(typeRef)
-        return if (forceNullableChain && pk != null) {
-            when (pk) {
-                PrimitiveKind.FLOAT -> "($left)?.toBits() == ($right)?.toBits()"
-                PrimitiveKind.DOUBLE -> "($left)?.toBits() == ($right)?.toBits()"
-                PrimitiveKind.BOOLEAN,
-                PrimitiveKind.BYTE,
-                PrimitiveKind.SHORT,
-                PrimitiveKind.INT,
-                PrimitiveKind.LONG,
-                PrimitiveKind.CHAR,
-                -> "$left == $right"
-            }
-        } else {
-            when (pk) {
-                PrimitiveKind.FLOAT -> "($left).toBits() == ($right).toBits()"
-                PrimitiveKind.DOUBLE -> "($left).toBits() == ($right).toBits()"
-                PrimitiveKind.BOOLEAN,
-                PrimitiveKind.BYTE,
-                PrimitiveKind.SHORT,
-                PrimitiveKind.INT,
-                PrimitiveKind.LONG,
-                PrimitiveKind.CHAR,
-                -> "$left == $right"
-                null -> if (isKotlinArrayType(typeRef)) "($left).contentEquals($right)" else "$left == $right"
-            }
+        if (pk != null) {
+            return primitiveEq(left, right, pk, nullSafe = forceNullableChain)
         }
+        return if (isKotlinArrayType(typeRef)) "($left).contentEquals($right)" else "$left == $right"
     }
 
     private fun identicalExpr(left: String, right: String, typeRef: KSTypeReference, forceNullableChain: Boolean): String {
         val pk = primitiveKind(typeRef)
-        return if (forceNullableChain && pk != null) {
-            when (pk) {
-                PrimitiveKind.FLOAT -> "($left)?.toBits() == ($right)?.toBits()"
-                PrimitiveKind.DOUBLE -> "($left)?.toBits() == ($right)?.toBits()"
-                PrimitiveKind.BOOLEAN,
-                PrimitiveKind.BYTE,
-                PrimitiveKind.SHORT,
-                PrimitiveKind.INT,
-                PrimitiveKind.LONG,
-                PrimitiveKind.CHAR,
-                -> "$left == $right"
-            }
-        } else {
-            when (pk) {
-                PrimitiveKind.FLOAT -> "($left).toBits() == ($right).toBits()"
-                PrimitiveKind.DOUBLE -> "($left).toBits() == ($right).toBits()"
-                PrimitiveKind.BOOLEAN,
-                PrimitiveKind.BYTE,
-                PrimitiveKind.SHORT,
-                PrimitiveKind.INT,
-                PrimitiveKind.LONG,
-                PrimitiveKind.CHAR,
-                -> "$left == $right"
-                null -> {
-                    if (isNullableKotlinPrimitive(typeRef)) return "$left == $right"
-                    if (isValueBasedType(typeRef)) "$left == $right" else "$left === $right"
-                }
-            }
+        if (pk != null) {
+            return primitiveEq(left, right, pk, nullSafe = forceNullableChain)
         }
+        if (isNullableKotlinPrimitive(typeRef)) return "$left == $right"
+        return if (isValueBasedType(typeRef)) "$left == $right" else "$left === $right"
+    }
+
+    /**
+     * Reports the key annotations that are not supported on inline record fields: @PK, @FK and @UK apply to
+     * top-level entity fields only.
+     */
+    private fun reportInlineKeyAnnotations(prop: KSPropertyDeclaration) {
+        if (hasAnnotationOrMeta(prop, PRIMARY_KEY)) {
+            logger.error(
+                "@PK is not supported on inline record fields. " +
+                    "Primary keys are only supported on top-level entity fields.",
+                prop,
+            )
+        }
+        if (hasAnnotationOrMeta(prop, FOREIGN_KEY)) {
+            logger.error(
+                "@FK is not supported on inline record fields. " +
+                    "Foreign keys are only supported on top-level entity fields.",
+                prop,
+            )
+        }
+        if (hasAnnotationOrMeta(prop, UNIQUE_KEY)) {
+            logger.error(
+                "@UK is not supported on inline record fields. " +
+                    "Unique keys are only supported on top-level entity fields.",
+                prop,
+            )
+        }
+    }
+
+    /**
+     * Returns the incremental-processing dependencies of a generated file: its declaration's containing file,
+     * or no sources for a declaration that has none (such as one from a library).
+     */
+    private fun dependenciesOf(classDeclaration: KSClassDeclaration): Dependencies {
+        val containingFile = classDeclaration.containingFile
+        return if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
     }
 
     private fun buildInterfaceFields(
@@ -914,27 +897,7 @@ class MetamodelProcessor(
                 // Validate: @PK, @FK, and @UK are not supported on inline record fields. Both chain variants walk
                 // the same properties; only the base pass reports, so a diagnostic prints once.
                 if (!forceNullableChain && !classDeclaration.implementsInterface(DATA)) {
-                    if (hasAnnotationOrMeta(prop, PRIMARY_KEY)) {
-                        logger.error(
-                            "@PK is not supported on inline record fields. " +
-                                "Primary keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
-                    if (hasAnnotationOrMeta(prop, FOREIGN_KEY)) {
-                        logger.error(
-                            "@FK is not supported on inline record fields. " +
-                                "Foreign keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
-                    if (hasAnnotationOrMeta(prop, UNIQUE_KEY)) {
-                        logger.error(
-                            "@UK is not supported on inline record fields. " +
-                                "Unique keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
+                    reportInlineKeyAnnotations(prop)
                 }
                 val inlineFlag = if (isChildData) "false" else "true"
                 val childForceNullable = forceNullableChain || propNullable
@@ -1022,27 +985,7 @@ class MetamodelProcessor(
                 // Validate: @PK, @FK, and @UK are not supported on inline record fields. Both chain variants walk
                 // the same properties; only the base pass reports, so a diagnostic prints once.
                 if (!forceNullableChain && !isData) {
-                    if (hasAnnotationOrMeta(prop, PRIMARY_KEY)) {
-                        logger.error(
-                            "@PK is not supported on inline record fields. " +
-                                "Primary keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
-                    if (hasAnnotationOrMeta(prop, FOREIGN_KEY)) {
-                        logger.error(
-                            "@FK is not supported on inline record fields. " +
-                                "Foreign keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
-                    if (hasAnnotationOrMeta(prop, UNIQUE_KEY)) {
-                        logger.error(
-                            "@UK is not supported on inline record fields. " +
-                                "Unique keys are only supported on top-level entity fields.",
-                            prop,
-                        )
-                    }
+                    reportInlineKeyAnnotations(prop)
                 }
                 val effectivelyNullable = if (!isData) {
                     // Leaf of a compound key: report raw field nullability for runtime derivation.
@@ -1230,8 +1173,7 @@ class MetamodelProcessor(
         val metaClassName = "Navigable${className}Metamodel"
         val navFields = buildNavClassFields(classDeclaration, packageName)
         val initFields = initNavClassFields(classDeclaration, packageName)
-        val containingFile = classDeclaration.containingFile
-        val deps = if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
+        val deps = dependenciesOf(classDeclaration)
         val file = codeGenerator.createNewFile(dependencies = deps, packageName = packageName, fileName = metaClassName)
         OutputStreamWriter(file).use { writer ->
             writer.write(
@@ -1275,8 +1217,7 @@ class MetamodelProcessor(
         val refType = "st.orm.Ref<$className>"
         val navFields = buildNavClassFields(classDeclaration, packageName)
         val initFields = initNavClassFields(classDeclaration, packageName)
-        val containingFile = classDeclaration.containingFile
-        val deps = if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
+        val deps = dependenciesOf(classDeclaration)
         val file = codeGenerator.createNewFile(dependencies = deps, packageName = packageName, fileName = metaClassName)
         OutputStreamWriter(file).use { writer ->
             writer.write(
@@ -1415,7 +1356,7 @@ class MetamodelProcessor(
         val componentNames = primaryConstructor.parameters.map { it.name?.asString() ?: return }
         val components = componentNames.joinToString(",\n") { "        instance.${escaped(it)}" }
         val containingFile = classDeclaration.containingFile
-        val deps = if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
+        val deps = dependenciesOf(classDeclaration)
         val file = codeGenerator.createNewFile(
             dependencies = deps,
             packageName = packageName,
@@ -1474,8 +1415,7 @@ class MetamodelProcessor(
         val packageName = classDeclaration.packageName.asString()
         val className = classDeclaration.simpleName.asString()
         val metaInterfaceName = "${className}_"
-        val containingFile = classDeclaration.containingFile
-        val deps = if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
+        val deps = dependenciesOf(classDeclaration)
         val file = codeGenerator.createNewFile(
             dependencies = deps,
             packageName = packageName,
@@ -1603,8 +1543,7 @@ class MetamodelProcessor(
             |    }
         """.trimMargin().trim('\n')
 
-        val containingFile = classDeclaration.containingFile
-        val deps = if (containingFile != null) Dependencies(true, containingFile) else Dependencies(false)
+        val deps = dependenciesOf(classDeclaration)
         val file = codeGenerator.createNewFile(
             dependencies = deps,
             packageName = packageName,
diff --git a/storm-metamodel-processor/src/main/java/st/orm/metamodel/MetamodelProcessor.java b/storm-metamodel-processor/src/main/java/st/orm/metamodel/MetamodelProcessor.java
index e612a6b0f..1245e6613 100644
--- a/storm-metamodel-processor/src/main/java/st/orm/metamodel/MetamodelProcessor.java
+++ b/storm-metamodel-processor/src/main/java/st/orm/metamodel/MetamodelProcessor.java
@@ -1111,11 +1111,7 @@ private void generateInstantiator(Element recordElement) {
             components.append(components.isEmpty() ? "" : ",\n")
                     .append("                instance.").append(parameters.get(i).getSimpleName()).append("()");
         }
-        try {
-            JavaFileObject fileObject = processingEnv.getFiler()
-                    .createSourceFile((packageName.isEmpty() ? "" : packageName + ".") + instantiatorName, recordElement);
-            try (Writer writer = fileObject.openWriter()) {
-                writer.write(String.format("""
+        writeSourceFile(packageName, instantiatorName, recordElement, String.format("""
                     %simport javax.annotation.processing.Generated;
 
                     /**
@@ -1157,11 +1153,7 @@ public Object[] deconstruct(%s instance) {
                         recordName,
                         components
                 ));
-            }
-            generatedInstantiators.add((packageName.isEmpty() ? "" : packageName + ".") + instantiatorName);
-        } catch (IOException e) {
-            throw new UncheckedIOException("Failed to write " + instantiatorName, e);
-        }
+        generatedInstantiators.add((packageName.isEmpty() ? "" : packageName + ".") + instantiatorName);
     }
 
     private void generateMetamodelInterface(Element recordElement) {
@@ -1171,35 +1163,37 @@ private void generateMetamodelInterface(Element recordElement) {
         String packageName = elementUtils.getPackageOf(recordElement).getQualifiedName().toString();
         String recordName = recordElement.getSimpleName().toString();
         String metaInterfaceName = recordName + "_";
-        try {
-            JavaFileObject fileObject = processingEnv.getFiler()
-                    .createSourceFile((packageName.isEmpty() ? "" : packageName + ".") + metaInterfaceName, recordElement);
-            try (Writer writer = fileObject.openWriter()) {
-                writer.write(String.format("""
-                    %simport st.orm.Metamodel;
-                    import st.orm.AbstractMetamodel;
-                    import st.orm.AbstractKeyMetamodel;
-                    import javax.annotation.processing.Generated;
+        writeMetamodelInterface(packageName, recordName, metaInterfaceName,
+                buildInterfaceFields(recordElement, packageName), recordElement);
+    }
 
-                    /**
-                     * Metamodel for %s.
-                     */
-                    @Generated("%s")
-                    public interface %s extends Metamodel<%s, %s> {
-                    %s
-                    }""",
-                        (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n"),
-                        recordName,
-                        getClass().getName(),
-                        metaInterfaceName,
-                        recordName,
-                        recordName,
-                        buildInterfaceFields(recordElement, packageName)
-                ));
-            }
-        } catch (IOException e) {
-            throw new UncheckedIOException("Failed to write " + metaInterfaceName, e);
-        }
+    /**
+     * Writes a metamodel interface: the per-field constants the callers assemble, wrapped in the shared
+     * interface shell.
+     */
+    private void writeMetamodelInterface(String packageName, String typeName, String metaInterfaceName,
+                                         String fields, Element originating) {
+        writeSourceFile(packageName, metaInterfaceName, originating, String.format("""
+            %simport st.orm.Metamodel;
+            import st.orm.AbstractMetamodel;
+            import st.orm.AbstractKeyMetamodel;
+            import javax.annotation.processing.Generated;
+
+            /**
+             * Metamodel for %s.
+             */
+            @Generated("%s")
+            public interface %s extends Metamodel<%s, %s> {
+            %s
+            }""",
+                (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n"),
+                typeName,
+                getClass().getName(),
+                metaInterfaceName,
+                typeName,
+                typeName,
+                fields
+        ));
     }
 
     private String buildClassFields(Element recordElement,
@@ -1277,24 +1271,7 @@ private String initClassFields(Element recordElement,
                 // Validate: @PK, @FK, and @UK are not supported on inline record fields. Both chain variants walk
                 // the same fields; only the base pass reports, so a diagnostic prints once.
                 if (!nullableChain && !implementsData(recordElement)) {
-                    if (hasAnnotationOrMeta(enclosed, PRIMARY_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@PK is not supported on inline record fields. "
-                                + "Primary keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
-                    if (hasAnnotationOrMeta(enclosed, FOREIGN_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@FK is not supported on inline record fields. "
-                                + "Foreign keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
-                    if (hasAnnotationOrMeta(enclosed, UNIQUE_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@UK is not supported on inline record fields. "
-                                + "Unique keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
+                    reportInlineKeyAnnotations(enclosed);
                 }
                 String inlineFlag = inline ? "true" : "false";
                 // Null-safe nested getter: parent record (root getter) can be null.
@@ -1349,24 +1326,7 @@ private String initClassFields(Element recordElement,
                 // Validate: @PK, @FK, and @UK are not supported on inline record fields. Both chain variants walk
                 // the same fields; only the base pass reports, so a diagnostic prints once.
                 if (!nullableChain && !isData) {
-                    if (hasAnnotationOrMeta(enclosed, PRIMARY_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@PK is not supported on inline record fields. "
-                                + "Primary keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
-                    if (hasAnnotationOrMeta(enclosed, FOREIGN_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@FK is not supported on inline record fields. "
-                                + "Foreign keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
-                    if (hasAnnotationOrMeta(enclosed, UNIQUE_KEY)) {
-                        processingEnv.getMessager().printMessage(ERROR,
-                                "@UK is not supported on inline record fields. "
-                                + "Unique keys are only supported on top-level entity fields.",
-                                enclosed);
-                    }
+                    reportInlineKeyAnnotations(enclosed);
                 }
                 String baseClass = (!isData || unique) ? "AbstractKeyMetamodel" : "AbstractMetamodel";
                 boolean effectivelyNullable = false;
@@ -1703,6 +1663,42 @@ private void writeSourceFile(String packageName, String className, Element origi
         }
     }
 
+    /**
+     * Renders the body of the root metamodel's isSame: reads both roots through the getter, treats a null
+     * root as equal only to another null, and applies the given comparison to the non-null pair.
+     */
+    private static String rootIsSameBody(String typeName, String comparison) {
+        return typeName + " ra = getter.apply(a);\n" +
+                "        " + typeName + " rb = getter.apply(b);\n" +
+                "        if (ra == null || rb == null) return ra == rb;\n" +
+                "        return " + comparison + ";";
+    }
+
+    /**
+     * Reports the key annotations that are not supported on inline record fields: @PK, @FK and @UK apply to
+     * top-level entity fields only.
+     */
+    private void reportInlineKeyAnnotations(Element enclosed) {
+        if (hasAnnotationOrMeta(enclosed, PRIMARY_KEY)) {
+            processingEnv.getMessager().printMessage(ERROR,
+                    "@PK is not supported on inline record fields. "
+                    + "Primary keys are only supported on top-level entity fields.",
+                    enclosed);
+        }
+        if (hasAnnotationOrMeta(enclosed, FOREIGN_KEY)) {
+            processingEnv.getMessager().printMessage(ERROR,
+                    "@FK is not supported on inline record fields. "
+                    + "Foreign keys are only supported on top-level entity fields.",
+                    enclosed);
+        }
+        if (hasAnnotationOrMeta(enclosed, UNIQUE_KEY)) {
+            processingEnv.getMessager().printMessage(ERROR,
+                    "@UK is not supported on inline record fields. "
+                    + "Unique keys are only supported on top-level entity fields.",
+                    enclosed);
+        }
+    }
+
     private void generateMetamodelClass(Element recordElement, boolean nullableChain) {
         String packageName = elementUtils.getPackageOf(recordElement).getQualifiedName().toString();
         String recordName = recordElement.getSimpleName().toString();
@@ -1711,7 +1707,7 @@ private void generateMetamodelClass(Element recordElement, boolean nullableChain
 
         // Root isSame: compare by PK if present, else compare by value, but guard for null root record.
         Optional<String> pkNameOpt = findPrimaryKeyFieldName(recordElement);
-        String rootIsSameBody;
+        String rootIsSameBody = null;
         if (pkNameOpt.isPresent()) {
             String pkName = pkNameOpt.get();
             TypeMirror pkType = getTypeElement(recordElement, pkName);
@@ -1720,174 +1716,160 @@ private void generateMetamodelClass(Element recordElement, boolean nullableChain
                     processingEnv.getMessager().printMessage(ERROR,
                             "Found @PK on '" + pkName + "' but could not resolve its type on " + recordName);
                 }
-                rootIsSameBody =
-                        recordName + " ra = getter.apply(a);\n" +
-                                "        " + recordName + " rb = getter.apply(b);\n" +
-                                "        if (ra == null || rb == null) return ra == rb;\n" +
-                                "        return Objects.equals(ra, rb);";
             } else {
                 String left = accessorExpr(recordElement, "ra", pkName, pkType);
                 String right = accessorExpr(recordElement, "rb", pkName, pkType);
-                rootIsSameBody =
-                        recordName + " ra = getter.apply(a);\n" +
-                                "        " + recordName + " rb = getter.apply(b);\n" +
-                                "        if (ra == null || rb == null) return ra == rb;\n" +
-                                "        return " + sameComparisonExpr(left, right, pkType) + ";";
+                rootIsSameBody = rootIsSameBody(recordName, sameComparisonExpr(left, right, pkType));
             }
-        } else {
-            rootIsSameBody =
-                    recordName + " ra = getter.apply(a);\n" +
-                            "        " + recordName + " rb = getter.apply(b);\n" +
-                            "        if (ra == null || rb == null) return ra == rb;\n" +
-                            "        return Objects.equals(ra, rb);";
+        }
+        if (rootIsSameBody == null) {
+            rootIsSameBody = rootIsSameBody(recordName, "Objects.equals(ra, rb)");
         }
 
-        try {
-            JavaFileObject fileObject = processingEnv.getFiler()
-                    .createSourceFile((packageName.isEmpty() ? "" : packageName + ".") + metaClassName, recordElement);
-
-            String classFields = buildClassFields(recordElement, packageName, recordName, nullableChain);
-            String initFields = initClassFields(recordElement, packageName, recordName, metaClassName, nullableChain);
-
-            String header =
-                    (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n") +
-                            "import st.orm.Metamodel;\n" +
-                            "import st.orm.AbstractMetamodel;\n" +
-                            "import st.orm.AbstractKeyMetamodel;\n" +
-                            "import javax.annotation.processing.Generated;\n" +
-                            "import java.util.Objects;\n\n" +
-                            "/**\n" +
-                            (nullableChain
-                                    ? " * Nullable-chain metamodel implementation for " + recordName
-                                            + ": a parent in the graph can be null, so every value read through it can be.\n"
-                                    : " * Metamodel implementation for " + recordName + ".\n") +
-                            " *\n" +
-                            " * @param <T> the record type of the root table of the entity graph.\n" +
-                            " */\n" +
-                            "@Generated(\"" + getClass().getName() + "\")\n" +
-                            "public final class " + metaClassName + "<T extends st.orm.Data> extends " + (isData ? "AbstractMetamodel" : "AbstractKeyMetamodel") + "<T, " + recordName + ", " + recordName + "> {\n\n";
-
-            String flattenMethod = buildFlattenMethod(recordElement, isData);
-
-            String isNullableOverride = "";
-            if (!isData) {
-                isNullableOverride =
-                        "    @Override\n" +
-                        "    @SuppressWarnings(\"rawtypes\")\n" +
-                        "    public boolean isNullable() {\n" +
-                        "        if (!super.isNullable()) return false;\n" +
-                        "        for (var leaf : flatten()) {\n" +
-                        "            if (leaf instanceof Metamodel.Key key && key.isNullable()) return true;\n" +
-                        "        }\n" +
-                        "        return false;\n" +
-                        "    }\n\n";
-            }
+        String classFields = buildClassFields(recordElement, packageName, recordName, nullableChain);
+        String initFields = initClassFields(recordElement, packageName, recordName, metaClassName, nullableChain);
+        String flattenMethod = buildFlattenMethod(recordElement, isData);
+
+        String isNullableOverride = "";
+        if (!isData) {
+            isNullableOverride =
+                    "    @Override\n" +
+                    "    @SuppressWarnings(\"rawtypes\")\n" +
+                    "    public boolean isNullable() {\n" +
+                    "        if (!super.isNullable()) return false;\n" +
+                    "        for (var leaf : flatten()) {\n" +
+                    "            if (leaf instanceof Metamodel.Key key && key.isNullable()) return true;\n" +
+                    "        }\n" +
+                    "        return false;\n" +
+                    "    }\n\n";
+        }
+
+        writeSourceFile(packageName, metaClassName, recordElement,
+                renderMetamodelClassSource(packageName, recordName, metaClassName, isData, nullableChain,
+                        rootIsSameBody, classFields, initFields, flattenMethod, isNullableOverride));
+    }
 
-            String body =
-                    classFields + "\n" +
-                            "    private final java.util.function.Function<T, " + recordName + "> getter;\n\n" +
-                            "    @Override\n" +
-                            "    public " + nullableReturnType(recordName) + " getValue(T record) {\n" +
-                            "        return getter.apply(record);\n" +
+    /**
+     * Renders a metamodel class: the shared shell around the pieces the record and sealed-interface
+     * generators derive differently (fields, initializers, the root isSame body, the flatten method and the
+     * optional isNullable override).
+     */
+    private String renderMetamodelClassSource(String packageName,
+                                              String typeName,
+                                              String metaClassName,
+                                              boolean isData,
+                                              boolean nullableChain,
+                                              String rootIsSameBody,
+                                              String classFields,
+                                              String initFields,
+                                              String flattenMethod,
+                                              String isNullableOverride) {
+        String header =
+                (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n") +
+                        "import st.orm.Metamodel;\n" +
+                        "import st.orm.AbstractMetamodel;\n" +
+                        "import st.orm.AbstractKeyMetamodel;\n" +
+                        "import javax.annotation.processing.Generated;\n" +
+                        "import java.util.Objects;\n\n" +
+                        "/**\n" +
+                        (nullableChain
+                                ? " * Nullable-chain metamodel implementation for " + typeName
+                                        + ": a parent in the graph can be null, so every value read through it can be.\n"
+                                : " * Metamodel implementation for " + typeName + ".\n") +
+                        " *\n" +
+                        " * @param <T> the record type of the root table of the entity graph.\n" +
+                        " */\n" +
+                        "@Generated(\"" + getClass().getName() + "\")\n" +
+                        "public final class " + metaClassName + "<T extends st.orm.Data> extends " + (isData ? "AbstractMetamodel" : "AbstractKeyMetamodel") + "<T, " + typeName + ", " + typeName + "> {\n\n";
+        String body =
+                classFields + "\n" +
+                        "    private final java.util.function.Function<T, " + typeName + "> getter;\n\n" +
+                        "    @Override\n" +
+                        "    public " + nullableReturnType(typeName) + " getValue(T record) {\n" +
+                        "        return getter.apply(record);\n" +
+                        "    }\n\n" +
+                        "    @Override\n" +
+                        "    public boolean isIdentical(T a, T b) {\n" +
+                        "        " + typeName + " ra = getter.apply(a);\n" +
+                        "        " + typeName + " rb = getter.apply(b);\n" +
+                        "        return ra == rb;\n" +
+                        "    }\n\n" +
+                        "    @Override\n" +
+                        "    public boolean isSame(T a, T b) {\n" +
+                        "        " + rootIsSameBody + "\n" +
+                        "    }\n\n" +
+                        flattenMethod +
+                        isNullableOverride;
+        String constructors;
+        if (isData) {
+            constructors =
+                    "    public " + metaClassName + "() {\n" +
+                            "        this(\"\", \"\", false, (Metamodel<T, ?>) Metamodel.root(" + typeName + ".class), " +
+                            "t -> (" + typeName + ") t);\n" +
                             "    }\n\n" +
-                            "    @Override\n" +
-                            "    public boolean isIdentical(T a, T b) {\n" +
-                            "        " + recordName + " ra = getter.apply(a);\n" +
-                            "        " + recordName + " rb = getter.apply(b);\n" +
-                            "        return ra == rb;\n" +
+                            "    public " + metaClassName + "(String field, Metamodel<T, ?> parent) {\n" +
+                            "        this(\"\", field, false, parent, t -> (" + typeName + ") t);\n" +
                             "    }\n\n" +
-                            "    @Override\n" +
-                            "    public boolean isSame(T a, T b) {\n" +
-                            "        " + rootIsSameBody + "\n" +
+                            "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent) {\n" +
+                            "        this(path, field, false, parent, t -> (" + typeName + ") t);\n" +
                             "    }\n\n" +
-                            flattenMethod +
-                            isNullableOverride;
-            String constructors;
-            if (isData) {
-                constructors =
-                        "    public " + metaClassName + "() {\n" +
-                                "        this(\"\", \"\", false, (Metamodel<T, ?>) Metamodel.root(" + recordName + ".class), " +
-                                "t -> (" + recordName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String field, Metamodel<T, ?> parent) {\n" +
-                                "        this(\"\", field, false, parent, t -> (" + recordName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent) {\n" +
-                                "        this(path, field, false, parent, t -> (" + recordName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + recordName + "> getter) {\n" +
-                                "        this(path, field, false, parent, getter);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent) {\n" +
-                                "        this(path, field, inline, parent, t -> (" + recordName + ") t);\n" +
-                                "    }\n\n";
-            } else {
-                constructors =
-                        "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + recordName + "> getter) {\n" +
-                                "        this(path, field, false, parent, getter);\n" +
-                                "    }\n\n";
-            }
-            String fullCtor;
-            if (isData) {
-                fullCtor =
-                        "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + recordName + "> getter) {\n" +
-                                "        super(" + recordName + ".class, path, field, inline, parent);\n" +
-                                "        this.getter = getter;\n\n" +
-                                "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
-                                "path + \".\" + field;\n" +
-                                "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
-                                initFields + "\n" +
-                                "    }\n";
-            } else {
-                fullCtor =
-                        "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + recordName + "> getter, boolean nullable) {\n" +
-                                "        super(" + recordName + ".class, path, field, inline, parent, !inline && !field.isEmpty(), nullable);\n" +
-                                "        this.getter = getter;\n\n" +
-                                "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
-                                "path + \".\" + field;\n" +
-                                "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
-                                initFields + "\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + recordName + "> getter) {\n" +
-                                "        this(path, field, inline, parent, getter, false);\n" +
-                                "    }\n";
-            }
-            String staticInstance = "";
-            if (isData && !nullableChain) {
-                staticInstance =
-                        "\n    @SuppressWarnings(\"rawtypes\")\n" +
-                        "    private static final " + metaClassName + " INSTANCE = new " + metaClassName + "();\n\n" +
-                        "    @SuppressWarnings(\"unchecked\")\n" +
-                        "    public static <T extends st.orm.Data> " + metaClassName + "<T> instance() {\n" +
-                        "        return INSTANCE;\n" +
-                        "    }\n";
-            }
-            String footer = "}\n";
-            try (Writer writer = fileObject.openWriter()) {
-                writer.write(header);
-                writer.write(body);
-                writer.write(constructors);
-                writer.write(fullCtor);
-                writer.write(staticInstance);
-                writer.write(footer);
-            }
-        } catch (IOException e) {
-            throw new UncheckedIOException("Failed to write " + metaClassName, e);
+                            "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
+                            "java.util.function.Function<T, " + typeName + "> getter) {\n" +
+                            "        this(path, field, false, parent, getter);\n" +
+                            "    }\n\n" +
+                            "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent) {\n" +
+                            "        this(path, field, inline, parent, t -> (" + typeName + ") t);\n" +
+                            "    }\n\n";
+        } else {
+            constructors =
+                    "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
+                            "java.util.function.Function<T, " + typeName + "> getter) {\n" +
+                            "        this(path, field, false, parent, getter);\n" +
+                            "    }\n\n";
+        }
+        String fullCtor;
+        if (isData) {
+            fullCtor =
+                    "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
+                            "java.util.function.Function<T, " + typeName + "> getter) {\n" +
+                            "        super(" + typeName + ".class, path, field, inline, parent);\n" +
+                            "        this.getter = getter;\n\n" +
+                            "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
+                            "path + \".\" + field;\n" +
+                            "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
+                            initFields + "\n" +
+                            "    }\n";
+        } else {
+            fullCtor =
+                    "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
+                            "java.util.function.Function<T, " + typeName + "> getter, boolean nullable) {\n" +
+                            "        super(" + typeName + ".class, path, field, inline, parent, !inline && !field.isEmpty(), nullable);\n" +
+                            "        this.getter = getter;\n\n" +
+                            "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
+                            "path + \".\" + field;\n" +
+                            "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
+                            initFields + "\n" +
+                            "    }\n\n" +
+                            "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
+                            "java.util.function.Function<T, " + typeName + "> getter) {\n" +
+                            "        this(path, field, inline, parent, getter, false);\n" +
+                            "    }\n";
+        }
+        String staticInstance = "";
+        if (isData && !nullableChain) {
+            staticInstance =
+                    "\n    @SuppressWarnings(\"rawtypes\")\n" +
+                    "    private static final " + metaClassName + " INSTANCE = new " + metaClassName + "();\n\n" +
+                    "    @SuppressWarnings(\"unchecked\")\n" +
+                    "    public static <T extends st.orm.Data> " + metaClassName + "<T> instance() {\n" +
+                    "        return INSTANCE;\n" +
+                    "    }\n";
         }
+        return header + body + constructors + fullCtor + staticInstance + "}\n";
     }
 
     // ---- Sealed interface support ----
 
-    private static boolean hasAnnotation(Element element, String annotationFqn) {
-        return element.getAnnotationMirrors().stream()
-                .anyMatch(am -> annotationFqn.equals(am.getAnnotationType().toString()));
-    }
-
     private static List<ExecutableElement> getDeclaredAbstractGetters(TypeElement sealedInterface) {
         return sealedInterface.getEnclosedElements().stream()
                 .filter(e -> e.getKind() == ElementKind.METHOD)
@@ -1914,11 +1896,6 @@ private boolean isPrimaryKeyOnSubclass(TypeElement sealedInterface, String field
         return firstRecord != null && isPrimaryKeyField(firstRecord, fieldName);
     }
 
-    private boolean isUniqueFieldOnSubclass(TypeElement sealedInterface, String fieldName) {
-        TypeElement firstRecord = getFirstPermittedRecord(sealedInterface);
-        return firstRecord != null && isUniqueField(firstRecord, fieldName);
-    }
-
     /**
      * Returns {@code true} if the field should be treated as a unique key for metamodel generation purposes.
      */
@@ -2027,35 +2004,7 @@ private void generateSealedMetamodelInterface(TypeElement sealedInterface,
             fields.setLength(fields.length() - 1);
         }
 
-        try {
-            JavaFileObject fileObject = processingEnv.getFiler()
-                    .createSourceFile((packageName.isEmpty() ? "" : packageName + ".") + metaInterfaceName, sealedInterface);
-            try (Writer writer = fileObject.openWriter()) {
-                writer.write(String.format("""
-                    %simport st.orm.Metamodel;
-                    import st.orm.AbstractMetamodel;
-                    import st.orm.AbstractKeyMetamodel;
-                    import javax.annotation.processing.Generated;
-
-                    /**
-                     * Metamodel for %s.
-                     */
-                    @Generated("%s")
-                    public interface %s extends Metamodel<%s, %s> {
-                    %s
-                    }""",
-                        (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n"),
-                        typeName,
-                        getClass().getName(),
-                        metaInterfaceName,
-                        typeName,
-                        typeName,
-                        fields.toString()
-                ));
-            }
-        } catch (IOException e) {
-            throw new UncheckedIOException("Failed to write " + metaInterfaceName, e);
-        }
+        writeMetamodelInterface(packageName, typeName, metaInterfaceName, fields.toString(), sealedInterface);
     }
 
     private void generateSealedMetamodelClass(TypeElement sealedInterface,
@@ -2082,17 +2031,9 @@ private void generateSealedMetamodelClass(TypeElement sealedInterface,
         if (pkName != null && pkType != null) {
             String left = "ra." + pkName + "()";
             String right = "rb." + pkName + "()";
-            rootIsSameBody =
-                    typeName + " ra = getter.apply(a);\n" +
-                            "        " + typeName + " rb = getter.apply(b);\n" +
-                            "        if (ra == null || rb == null) return ra == rb;\n" +
-                            "        return " + sameComparisonExpr(left, right, pkType) + ";";
+            rootIsSameBody = rootIsSameBody(typeName, sameComparisonExpr(left, right, pkType));
         } else {
-            rootIsSameBody =
-                    typeName + " ra = getter.apply(a);\n" +
-                            "        " + typeName + " rb = getter.apply(b);\n" +
-                            "        if (ra == null || rb == null) return ra == rb;\n" +
-                            "        return Objects.equals(ra, rb);";
+            rootIsSameBody = rootIsSameBody(typeName, "Objects.equals(ra, rb)");
         }
 
         // Build class fields.
@@ -2254,125 +2195,8 @@ private void generateSealedMetamodelClass(TypeElement sealedInterface,
         flattenMethod.append("    }\n\n");
 
         // Assemble the class.
-        try {
-            JavaFileObject fileObject = processingEnv.getFiler()
-                    .createSourceFile((packageName.isEmpty() ? "" : packageName + ".") + metaClassName, sealedInterface);
-
-            String header =
-                    (packageName.isEmpty() ? "" : "package " + packageName + ";\n\n") +
-                            "import st.orm.Metamodel;\n" +
-                            "import st.orm.AbstractMetamodel;\n" +
-                            "import st.orm.AbstractKeyMetamodel;\n" +
-                            "import javax.annotation.processing.Generated;\n" +
-                            "import java.util.Objects;\n\n" +
-                            "/**\n" +
-                            (nullableChain
-                                    ? " * Nullable-chain metamodel implementation for " + typeName
-                                            + ": a parent in the graph can be null, so every value read through it can be.\n"
-                                    : " * Metamodel implementation for " + typeName + ".\n") +
-                            " *\n" +
-                            " * @param <T> the record type of the root table of the entity graph.\n" +
-                            " */\n" +
-                            "@Generated(\"" + getClass().getName() + "\")\n" +
-                            "public final class " + metaClassName + "<T extends st.orm.Data> extends " +
-                            (isData ? "AbstractMetamodel" : "AbstractKeyMetamodel") + "<T, " + typeName + ", " + typeName + "> {\n\n";
-
-            String body =
-                    classFields + "\n" +
-                            "    private final java.util.function.Function<T, " + typeName + "> getter;\n\n" +
-                            "    @Override\n" +
-                            "    public " + nullableReturnType(typeName) + " getValue(T record) {\n" +
-                            "        return getter.apply(record);\n" +
-                            "    }\n\n" +
-                            "    @Override\n" +
-                            "    public boolean isIdentical(T a, T b) {\n" +
-                            "        " + typeName + " ra = getter.apply(a);\n" +
-                            "        " + typeName + " rb = getter.apply(b);\n" +
-                            "        return ra == rb;\n" +
-                            "    }\n\n" +
-                            "    @Override\n" +
-                            "    public boolean isSame(T a, T b) {\n" +
-                            "        " + rootIsSameBody + "\n" +
-                            "    }\n\n" +
-                            flattenMethod;
-
-            String constructors;
-            if (isData) {
-                constructors =
-                        "    public " + metaClassName + "() {\n" +
-                                "        this(\"\", \"\", false, (Metamodel<T, ?>) Metamodel.root(" + typeName + ".class), " +
-                                "t -> (" + typeName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String field, Metamodel<T, ?> parent) {\n" +
-                                "        this(\"\", field, false, parent, t -> (" + typeName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent) {\n" +
-                                "        this(path, field, false, parent, t -> (" + typeName + ") t);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + typeName + "> getter) {\n" +
-                                "        this(path, field, false, parent, getter);\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent) {\n" +
-                                "        this(path, field, inline, parent, t -> (" + typeName + ") t);\n" +
-                                "    }\n\n";
-            } else {
-                constructors =
-                        "    public " + metaClassName + "(String path, String field, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + typeName + "> getter) {\n" +
-                                "        this(path, field, false, parent, getter);\n" +
-                                "    }\n\n";
-            }
-
-            String fullCtor;
-            if (isData) {
-                fullCtor =
-                        "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + typeName + "> getter) {\n" +
-                                "        super(" + typeName + ".class, path, field, inline, parent);\n" +
-                                "        this.getter = getter;\n\n" +
-                                "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
-                                "path + \".\" + field;\n" +
-                                "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
-                                initFields + "\n" +
-                                "    }\n";
-            } else {
-                fullCtor =
-                        "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + typeName + "> getter, boolean nullable) {\n" +
-                                "        super(" + typeName + ".class, path, field, inline, parent, !inline && !field.isEmpty(), nullable);\n" +
-                                "        this.getter = getter;\n\n" +
-                                "        String subPath = inline ? path : field.isEmpty() ? path : path.isEmpty() ? field : " +
-                                "path + \".\" + field;\n" +
-                                "        String fieldBase = inline ? (field.isEmpty() ? \"\" : field + \".\") : \"\";\n\n" +
-                                initFields + "\n" +
-                                "    }\n\n" +
-                                "    public " + metaClassName + "(String path, String field, boolean inline, Metamodel<T, ?> parent, " +
-                                "java.util.function.Function<T, " + typeName + "> getter) {\n" +
-                                "        this(path, field, inline, parent, getter, false);\n" +
-                                "    }\n";
-            }
-            String staticInstance = "";
-            if (isData && !nullableChain) {
-                staticInstance =
-                        "\n    @SuppressWarnings(\"rawtypes\")\n" +
-                        "    private static final " + metaClassName + " INSTANCE = new " + metaClassName + "();\n\n" +
-                        "    @SuppressWarnings(\"unchecked\")\n" +
-                        "    public static <T extends st.orm.Data> " + metaClassName + "<T> instance() {\n" +
-                        "        return INSTANCE;\n" +
-                        "    }\n";
-            }
-            String footer = "}\n";
-            try (Writer writer = fileObject.openWriter()) {
-                writer.write(header);
-                writer.write(body);
-                writer.write(constructors);
-                writer.write(fullCtor);
-                writer.write(staticInstance);
-                writer.write(footer);
-            }
-        } catch (IOException e) {
-            throw new UncheckedIOException("Failed to write " + metaClassName, e);
-        }
+        writeSourceFile(packageName, metaClassName, sealedInterface,
+                renderMetamodelClassSource(packageName, typeName, metaClassName, isData, nullableChain,
+                        rootIsSameBody, classFields.toString(), initFields.toString(), flattenMethod.toString(), ""));
     }
 }
diff --git a/storm-micrometer/src/main/java/st/orm/micrometer/OtelDatabaseObservationConvention.java b/storm-micrometer/src/main/java/st/orm/micrometer/OtelDatabaseObservationConvention.java
index 280e921b3..8ea5aeecd 100644
--- a/storm-micrometer/src/main/java/st/orm/micrometer/OtelDatabaseObservationConvention.java
+++ b/storm-micrometer/src/main/java/st/orm/micrometer/OtelDatabaseObservationConvention.java
@@ -97,8 +97,9 @@ public KeyValues getLowCardinalityKeyValues(StormQueryObservationContext context
 
     @Override
     public KeyValues getHighCardinalityKeyValues(StormQueryObservationContext context) {
+        var keyValues = super.getHighCardinalityKeyValues(context);
         return context.queryContext().statement()
-                .map(statement -> super.getHighCardinalityKeyValues(context).and("db.query.text", statement))
-                .orElseGet(() -> super.getHighCardinalityKeyValues(context));
+                .map(statement -> keyValues.and("db.query.text", statement))
+                .orElse(keyValues);
     }
 }
diff --git a/storm-micrometer/src/main/java/st/orm/micrometer/QueryObservers.java b/storm-micrometer/src/main/java/st/orm/micrometer/QueryObservers.java
index dbe1b8398..587f39fc1 100644
--- a/storm-micrometer/src/main/java/st/orm/micrometer/QueryObservers.java
+++ b/storm-micrometer/src/main/java/st/orm/micrometer/QueryObservers.java
@@ -54,9 +54,6 @@ public static QueryObserver create(
             @Nullable ObservationConvention<StormTransactionObservationContext> transactionConvention,
             @Nullable String database) {
         var keyValues = database == null ? KeyValues.empty() : KeyValues.of("storm.database", database);
-        if (queryConvention == null && transactionConvention == null) {
-            return new MicrometerQueryObserver(observationRegistry, keyValues);
-        }
         return new MicrometerQueryObserver(
                 observationRegistry,
                 queryConvention != null ? queryConvention : new StormQueryObservationConvention(),
diff --git a/storm-mssqlserver/pom.xml b/storm-mssqlserver/pom.xml
index 2f4f2ec68..385aff8b8 100644
--- a/storm-mssqlserver/pom.xml
+++ b/storm-mssqlserver/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.mssqlserver.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -101,6 +101,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerEntityRepositoryImpl.java b/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerEntityRepositoryImpl.java
index 7d74eeedd..b74709acd 100644
--- a/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerEntityRepositoryImpl.java
+++ b/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerEntityRepositoryImpl.java
@@ -18,7 +18,6 @@
 import static st.orm.GenerationStrategy.IDENTITY;
 import static st.orm.GenerationStrategy.NONE;
 import static st.orm.GenerationStrategy.SEQUENCE;
-import static st.orm.core.repository.impl.StreamSupport.partitioned;
 import static st.orm.core.template.SqlInterceptor.intercept;
 import static st.orm.core.template.TemplateString.combine;
 import static st.orm.core.template.TemplateString.raw;
@@ -26,22 +25,17 @@
 import static st.orm.core.template.impl.StringTemplates.flatten;
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Objects;
-import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import st.orm.Entity;
-import st.orm.Metamodel;
 import st.orm.PersistenceException;
 import st.orm.core.repository.EntityRepository;
 import st.orm.core.repository.impl.MergeEntityRepositoryImpl;
 import st.orm.core.template.Column;
 import st.orm.core.template.Model;
 import st.orm.core.template.ORMTemplate;
-import st.orm.core.template.PreparedQuery;
 import st.orm.core.template.Query;
 import st.orm.core.template.SqlTemplateException;
 import st.orm.core.template.TemplateString;
@@ -158,20 +152,6 @@ protected TemplateString mergeInsert() {
         return TemplateString.of("\nWHEN NOT MATCHED THEN%s".formatted(sql));
     }
 
-    // Partition keys for the SEQUENCE-specific upsertAndFetchIds.
-    private sealed interface SeqPartitionKey {}
-    private static final class SeqNoOpKey implements SeqPartitionKey {
-        private static final SeqNoOpKey INSTANCE = new SeqNoOpKey();
-    }
-    private static final class SeqUpsertKey implements SeqPartitionKey {
-        private static final SeqUpsertKey INSTANCE = new SeqUpsertKey();
-    }
-    private record SeqUpdateKey(Set<Metamodel<?, ?>> fields) implements SeqPartitionKey {
-        SeqUpdateKey() {
-            this(Set.of()); // All fields.
-        }
-    }
-
     /**
      * Overrides to use SEQUENCE-specific OUTPUT clause for batch fetch IDs when applicable.
      *
@@ -207,49 +187,8 @@ public List<ID> upsertAndFetchIds(Iterable<E> entities) {
                     "Use the column's DEFAULT constraint for sequence values instead.");
         }
         // SEQUENCE path with empty sequence: use a single query with OUTPUT clause instead of batched prepared statements.
-        Map<Set<Metamodel<?, ?>>, PreparedQuery> updateQueries = new HashMap<>();
-        try {
-            var result = new ArrayList<ID>();
-            var entityCache = entityCache();
-            partitioned(toStream(entities), defaultBatchSize, entity -> {
-                if (isUpsertUpdate(entity)) {
-                    var dirty = getDirty(entity, entityCache.orElse(null));
-                    if (dirty.isEmpty()) {
-                        return SeqNoOpKey.INSTANCE;
-                    }
-                    return new SeqUpdateKey(dirty.get());
-                } else {
-                    return SeqUpsertKey.INSTANCE;
-                }
-            }, getMaxShapes(), new SeqUpdateKey()).forEach(partition -> {
-                switch (partition.key()) {
-                    case SeqNoOpKey ignore -> result.addAll(partition.chunk().stream().map(E::id).toList());
-                    case SeqUpsertKey ignore -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpsert).toList()
-                                : partition.chunk();
-                        // Remove from cache entities with non-default PKs (could be updates via MERGE).
-                        entityCache.ifPresent(cache -> batch.stream()
-                                .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                                .forEach(e -> cache.remove(e.id())));
-                        List<ID> ids = getUpsertQuery(batch).getResultList(model.primaryKeyType());
-                        result.addAll(ids);
-                        fireAfterUpsert(batch, ids);
-                    }
-                    case SeqUpdateKey u -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpdate).toList()
-                                : partition.chunk();
-                        result.addAll(updateAndFetchIds(batch,
-                                updateQueries.computeIfAbsent(u.fields(), this::prepareUpdateQuery),
-                                entityCache.orElse(null)));
-                    }
-                }
-            });
-            return result;
-        } finally {
-            closeQuietly(updateQueries.values().stream());
-        }
+        return upsertAndFetchIdsPartitioned(entities,
+                (chunk, entityCache) -> upsertPartitionAndFetchIds(chunk, entityCache, this::getUpsertQuery));
     }
 
     private Query getUpsertQuery(Iterable<E> entities) {
diff --git a/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerSqlDialect.java b/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerSqlDialect.java
index 28a72c2df..5eb230be9 100644
--- a/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerSqlDialect.java
+++ b/storm-mssqlserver/src/main/java/st/orm/spi/mssqlserver/MSSQLServerSqlDialect.java
@@ -24,9 +24,8 @@
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
 import st.orm.core.template.Column;
-import st.orm.core.template.SqlDialect;
 
-public class MSSQLServerSqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class MSSQLServerSqlDialect extends DefaultSqlDialect {
 
     public MSSQLServerSqlDialect() {
     }
@@ -56,18 +55,6 @@ public boolean supportsDeleteAlias() {
         return true;
     }
 
-    /**
-     * Indicates whether the SQL dialect supports multi-value tuples in the IN clause.
-     *
-     * @return {@code true} if multi-value tuples are supported, {@code false} otherwise.
-     * @since 1.2
-     */
-    @Override
-    public boolean supportsMultiValueTuples() {
-        // SQL Server does not support multi-value tuple IN clauses.
-        return false;
-    }
-
     /**
      * Returns the selected columns rather than the key alone.
      *
@@ -144,22 +131,6 @@ public Pattern getIdentifierPattern() {
         return IDENTIFIER_PATTERN;
     }
 
-    /**
-     * Regex for single-quoted string literals, handling both double single quotes and backslash escapes.
-     */
-    private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile("'(?:''|\\\\.|[^'\\\\])*'");
-
-    /**
-     * Returns the pattern for string literals.
-     *
-     * @return the pattern for string literals.
-     * @since 1.2
-     */
-    @Override
-    public Pattern getQuoteLiteralPattern() {
-        return QUOTE_LITERAL_PATTERN;
-    }
-
     /**
      * Returns {@code true} if the limit should be applied after the SELECT clause, {@code false} to apply the limit at
      * the end of the query.
diff --git a/storm-mssqlserver/src/test/java/st/orm/spi/mssqlserver/testsupport/TestSpringConnectionProvider.java b/storm-mssqlserver/src/test/java/st/orm/spi/mssqlserver/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index a8d6665a2..000000000
--- a/storm-mssqlserver/src/test/java/st/orm/spi/mssqlserver/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.mssqlserver.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-mssqlserver/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-mssqlserver/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index ed8241117..b51953f70 100644
--- a/storm-mssqlserver/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-mssqlserver/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.mssqlserver.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-mysql/pom.xml b/storm-mysql/pom.xml
index bd9eb5173..9b90e7644 100644
--- a/storm-mysql/pom.xml
+++ b/storm-mysql/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.mysql.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -68,6 +68,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-mysql/src/main/java/st/orm/spi/mysql/MySQLSqlDialect.java b/storm-mysql/src/main/java/st/orm/spi/mysql/MySQLSqlDialect.java
index 595934059..3e41257ed 100644
--- a/storm-mysql/src/main/java/st/orm/spi/mysql/MySQLSqlDialect.java
+++ b/storm-mysql/src/main/java/st/orm/spi/mysql/MySQLSqlDialect.java
@@ -24,9 +24,8 @@
 import st.orm.PersistenceException;
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
-import st.orm.core.template.SqlDialect;
 
-public class MySQLSqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class MySQLSqlDialect extends DefaultSqlDialect {
 
     public MySQLSqlDialect() {
     }
@@ -140,22 +139,6 @@ public Pattern getIdentifierPattern() {
         return IDENTIFIER_PATTERN;
     }
 
-    /**
-     * Regex for single-quoted string literals, handling both double single quotes and backslash escapes.
-     */
-    private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile("'(?:''|\\\\.|[^'\\\\])*'");
-
-    /**
-     * Returns the pattern for string literals.
-     *
-     * @return the pattern for string literals.
-     * @since 1.2
-     */
-    @Override
-    public Pattern getQuoteLiteralPattern() {
-        return QUOTE_LITERAL_PATTERN;
-    }
-
     /**
      * Returns whether a multi-column comparison renders as a row value tuple, which for MySQL is the case for a
      * multi-row list only.
diff --git a/storm-mysql/src/test/java/st/orm/spi/mysql/testsupport/TestSpringConnectionProvider.java b/storm-mysql/src/test/java/st/orm/spi/mysql/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index 4ce89d4c3..000000000
--- a/storm-mysql/src/test/java/st/orm/spi/mysql/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.mysql.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-mysql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-mysql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index 0c1629510..b51953f70 100644
--- a/storm-mysql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-mysql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.mysql.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-oracle/pom.xml b/storm-oracle/pom.xml
index 96457e405..7c650ac85 100644
--- a/storm-oracle/pom.xml
+++ b/storm-oracle/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.oracle.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -68,6 +68,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-oracle/src/main/java/st/orm/spi/oracle/OracleSqlDialect.java b/storm-oracle/src/main/java/st/orm/spi/oracle/OracleSqlDialect.java
index f43336b83..0e88bd59c 100644
--- a/storm-oracle/src/main/java/st/orm/spi/oracle/OracleSqlDialect.java
+++ b/storm-oracle/src/main/java/st/orm/spi/oracle/OracleSqlDialect.java
@@ -8,7 +8,7 @@
  *      https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
@@ -24,15 +24,13 @@
 
 import java.util.List;
 import java.util.Set;
-import java.util.regex.Pattern;
 import java.util.stream.Stream;
 import st.orm.Operator;
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
 import st.orm.core.template.Column;
-import st.orm.core.template.SqlDialect;
 
-public class OracleSqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class OracleSqlDialect extends DefaultSqlDialect {
 
     public OracleSqlDialect() {
     }
@@ -52,20 +50,6 @@ public String name() {
         return "Oracle";
     }
 
-    /**
-     * Indicates whether the SQL dialect supports delete aliases.
-     *
-     * <p>Delete aliases allow delete statements to use table aliases in joins,  making it easier to filter rows based
-     * on related data.</p>
-     *
-     * @return {@code true} if delete aliases are supported, {@code false} otherwise.
-     */
-    @Override
-    public boolean supportsDeleteAlias() {
-        // Oracle doesn't allow table aliases in DELETE.
-        return false;
-    }
-
     /**
      * Indicates whether the SQL dialect supports multi-value tuples in the IN clause.
      *
@@ -90,19 +74,6 @@ public List<Column> groupBy(List<Column> key, List<Column> selected) {
         return selected;
     }
 
-    private static final Pattern ORACLE_IDENTIFIER = Pattern.compile("^[A-Za-z][A-Za-z0-9_]*$");
-
-    /**
-     * Returns the pattern for valid identifiers.
-     *
-     * @return the pattern for valid identifiers.
-     * @since 1.2
-     */
-    @Override
-    public Pattern getValidIdentifierPattern() {
-        return ORACLE_IDENTIFIER;
-    }
-
     private static final Set<String> ORACLE_RESERVED = Stream.concat(ANSI_KEYWORDS.stream(), Stream.of(
             "ACCESS", "AUDIT", "CLUSTER", "COMMENT", "COMPRESS", "EXCLUSIVE", "FILE", "IDENTIFIED",
             "INCREMENT", "INDEX", "INITIAL", "LOCK", "LONG", "MAXEXTENTS", "MLSLABEL", "MODE", "MODIFY", "NOWAIT",
@@ -127,28 +98,6 @@ public String escape(String name) {
         return "\"%s\"".formatted(name.replace("\"", "\"\""));
     }
 
-    /**
-     * Regex for double-quoted identifiers in Oracle (embedded quotes are doubled).
-     */
-    private static final Pattern IDENTIFIER_PATTERN = Pattern.compile(
-        "\"(?:\"\"|[^\"])*\""
-    );
-
-    @Override
-    public Pattern getIdentifierPattern() {
-        return IDENTIFIER_PATTERN;
-    }
-
-    /**
-     * Regex for single-quoted string literals in Oracle (escaped by doubling the single quote).
-     */
-    private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile("'(?:''|\\\\.|[^'\\\\])*'");
-
-    @Override
-    public Pattern getQuoteLiteralPattern() {
-        return QUOTE_LITERAL_PATTERN;
-    }
-
     /**
      * Returns whether a multi-column comparison renders as a row value tuple, which for Oracle is the case for an
      * ordering comparison and for a multi-row list.
@@ -235,17 +184,6 @@ public String forShareLockHint() {
         return "";
     }
 
-    /**
-     * Returns the lock hint for a write lock in Oracle.
-     * Oracle supports "FOR UPDATE" to lock rows for update.
-     *
-     * @return the lock hint for a write lock.
-     */
-    @Override
-    public String forUpdateLockHint() {
-        return "FOR UPDATE";
-    }
-
     /**
      * Returns the strategy for discovering sequences in the database schema.
      *
diff --git a/storm-oracle/src/test/java/st/orm/spi/oracle/testsupport/TestSpringConnectionProvider.java b/storm-oracle/src/test/java/st/orm/spi/oracle/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index a3ce3d992..000000000
--- a/storm-oracle/src/test/java/st/orm/spi/oracle/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.oracle.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-oracle/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-oracle/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index 12a418db8..b51953f70 100644
--- a/storm-oracle/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-oracle/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.oracle.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-postgresql/pom.xml b/storm-postgresql/pom.xml
index ee90032c4..43ce5ed37 100644
--- a/storm-postgresql/pom.xml
+++ b/storm-postgresql/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.postgresql.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -101,6 +101,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLEntityRepositoryImpl.java b/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLEntityRepositoryImpl.java
index b14a2f28a..bf28f5803 100644
--- a/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLEntityRepositoryImpl.java
+++ b/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLEntityRepositoryImpl.java
@@ -15,129 +15,34 @@
  */
 package st.orm.spi.postgresql;
 
-import static java.util.function.Predicate.not;
 import static st.orm.GenerationStrategy.SEQUENCE;
-import static st.orm.core.repository.impl.StreamSupport.partitioned;
 import static st.orm.core.template.SqlInterceptor.intercept;
-import static st.orm.core.template.TemplateString.combine;
 import static st.orm.core.template.TemplateString.raw;
-import static st.orm.core.template.Templates.table;
 import static st.orm.core.template.impl.StringTemplates.flatten;
 
-import java.math.BigInteger;
-import java.sql.Timestamp;
-import java.time.Instant;
-import java.util.ArrayList;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.stream.IntStream;
-import org.jspecify.annotations.Nullable;
-import st.orm.Data;
 import st.orm.Entity;
-import st.orm.Metamodel;
-import st.orm.NoResultException;
-import st.orm.NonUniqueResultException;
-import st.orm.PersistenceException;
 import st.orm.core.repository.EntityRepository;
-import st.orm.core.repository.impl.EntityRepositoryImpl;
-import st.orm.core.spi.EntityCache;
-import st.orm.core.template.Column;
+import st.orm.core.repository.impl.OnConflictEntityRepositoryImpl;
 import st.orm.core.template.Model;
 import st.orm.core.template.ORMTemplate;
-import st.orm.core.template.PreparedQuery;
 import st.orm.core.template.Query;
-import st.orm.core.template.TemplateString;
 
 /**
  * Implementation of {@link EntityRepository} for PostgreSQL.
  */
 public class PostgreSQLEntityRepositoryImpl<E extends Entity<ID>, ID>
-        extends EntityRepositoryImpl<E, ID> {
+        extends OnConflictEntityRepositoryImpl<E, ID> {
 
     public PostgreSQLEntityRepositoryImpl(ORMTemplate ormTemplate, Model<E, ID> model) {
         super(ormTemplate, model);
     }
 
-    private TemplateString getVersionString(Class<? extends Data> type, Column column) {
-        TemplateString columnName = TemplateString.of(column.qualifiedName(ormTemplate.dialect()));
-        TemplateString updateExpression = switch (column.type()) {
-            case Class<?> c when Integer.TYPE.isAssignableFrom(c)
-                    || Long.TYPE.isAssignableFrom(c)
-                    || Integer.class.isAssignableFrom(c)
-                    || Long.class.isAssignableFrom(c)
-                    || BigInteger.class.isAssignableFrom(c) -> raw("\0.\0 + 1", table(type), columnName);
-            case Class<?> c when Instant.class.isAssignableFrom(c)
-                    || Date.class.isAssignableFrom(c)
-                    || Calendar.class.isAssignableFrom(c)
-                    || Timestamp.class.isAssignableFrom(c) -> TemplateString.of("CURRENT_TIMESTAMP");
-            default ->
-                    throw new PersistenceException("Unsupported version type: %s.".formatted(column.type().getSimpleName()));
-        };
-        return flatten(raw("\0 = \0", columnName, updateExpression));
-    }
-
-    /**
-     * Constructs the PostgreSQL conflict clause for an upsert.
-     * <p>
-     * This method builds an "ON CONFLICT (<primary_keys>) DO UPDATE SET ..." clause.
-     * For non-primary key columns, it assigns the value from the EXCLUDED pseudo‑table.
-     * Version columns are updated using {@link #getVersionString(Class, Column)}.
-     * </p>
-     *
-     * @param versionAware a flag that will be set if a version column is encountered.
-     * @return the conflict clause as a TemplateString.
-     */
-    private TemplateString onConflictClause(AtomicBoolean versionAware) {
-        var dialect = ormTemplate.dialect();
-        // Determine the conflict target from primary key columns.
-        String conflictTarget = model.declaredColumns().stream()
-                .filter(Column::primaryKey)
-                .map(c -> c.qualifiedName(dialect))
-                .reduce("%s, %s"::formatted)
-                .orElseThrow(() -> new PersistenceException("No primary key defined."));
-        // Build the assignment list for non-primary key updatable columns.
-        var assignments = model.declaredColumns().stream()
-                .filter(not(Column::primaryKey))
-                .filter(Column::updatable)
-                .map(column -> {
-                    if (column.version()) {
-                        versionAware.setPlain(true);
-                        return getVersionString(model.type(), column);
-                    }
-                    return TemplateString.of("%s = EXCLUDED.%s".formatted(column.qualifiedName(dialect), column.qualifiedName(dialect)));
-                })
-                .reduce((left, right) -> combine(left, TemplateString.of(", "), right))
-                .map(st -> combine(TemplateString.of("DO UPDATE SET "), st))
-                .orElse(TemplateString.of("DO NOTHING"));
-        return flatten(combine(TemplateString.of("\nON CONFLICT ("), TemplateString.of(conflictTarget), raw(") \0", assignments)));
-    }
-
-    @Override
-    protected void doUpsert(E entity) {
-        validateUpsert(entity);
-        entityCache().ifPresent(cache -> {
-            if (!model.isDefaultPrimaryKey(entity.id())) {
-                cache.remove(entity.id());
-            }
-        });
-        var versionAware = new AtomicBoolean();
-        intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
-            var query = ormTemplate.query(flatten(raw("""
-                    INSERT INTO \0
-                    VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed();
-            query.executeUpdate();
-        });
-    }
-
     @Override
     protected ID doUpsertAndFetchId(E entity) {
         if (generationStrategy != SEQUENCE) {
-            return doUpsertAndFetchIdNoSequence(entity);
+            return super.doUpsertAndFetchId(entity);
         }
         validateUpsert(entity);
         entityCache().ifPresent(cache -> {
@@ -159,45 +64,6 @@ protected ID doUpsertAndFetchId(E entity) {
         });
     }
 
-    private ID doUpsertAndFetchIdNoSequence(E entity) {
-        validateUpsert(entity);
-        entityCache().ifPresent(cache -> {
-            if (!model.isDefaultPrimaryKey(entity.id())) {
-                cache.remove(entity.id());
-            }
-        });
-        var versionAware = new AtomicBoolean();
-        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
-            try (var query = ormTemplate.query(flatten(raw("""
-                        INSERT INTO \0
-                        VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed().prepare()) {
-                query.executeUpdate();
-                if (isAutoGeneratedPrimaryKey()) {
-                    try (var stream = query.getGeneratedKeys(model.primaryKeyType())) {
-                        return stream.reduce((ignore1, ignore2) -> {
-                            throw new NonUniqueResultException("Expected single result, but found more than one.");
-                        }).orElseThrow(() -> new NoResultException("Expected single result, but found none."));
-                    }
-                }
-                return entity.id();
-            }
-        });
-    }
-
-    // Partition keys for the SEQUENCE-specific upsertAndFetchIds.
-    private sealed interface SeqPartitionKey {}
-    private static final class SeqNoOpKey implements SeqPartitionKey {
-        private static final SeqNoOpKey INSTANCE = new SeqNoOpKey();
-    }
-    private static final class SeqUpsertKey implements SeqPartitionKey {
-        private static final SeqUpsertKey INSTANCE = new SeqUpsertKey();
-    }
-    private record SeqUpdateKey(Set<Metamodel<?, ?>> fields) implements SeqPartitionKey {
-        SeqUpdateKey() {
-            this(Set.of());
-        }
-    }
-
     /**
      * Overrides to use SEQUENCE-specific RETURNING clause for batch fetch IDs when applicable.
      */
@@ -207,49 +73,8 @@ public List<ID> upsertAndFetchIds(Iterable<E> entities) {
             return super.upsertAndFetchIds(entities);
         }
         // SEQUENCE path: use a single query with RETURNING clause instead of batched prepared statements.
-        Map<Set<Metamodel<?, ?>>, PreparedQuery> updateQueries = new HashMap<>();
-        try {
-            var result = new ArrayList<ID>();
-            var entityCache = entityCache();
-            partitioned(toStream(entities), defaultBatchSize, entity -> {
-                if (isUpsertUpdate(entity)) {
-                    var dirty = getDirty(entity, entityCache.orElse(null));
-                    if (dirty.isEmpty()) {
-                        return SeqNoOpKey.INSTANCE;
-                    }
-                    return new SeqUpdateKey(dirty.get());
-                } else {
-                    return SeqUpsertKey.INSTANCE;
-                }
-            }, getMaxShapes(), new SeqUpdateKey()).forEach(partition -> {
-                switch (partition.key()) {
-                    case SeqNoOpKey ignore -> result.addAll(partition.chunk().stream().map(E::id).toList());
-                    case SeqUpsertKey ignore -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpsert).toList()
-                                : partition.chunk();
-                        // Remove from cache entities with non-default PKs (could be updates via ON CONFLICT).
-                        entityCache.ifPresent(cache -> batch.stream()
-                                .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                                .forEach(e -> cache.remove(e.id())));
-                        List<ID> ids = getUpsertQuery(batch).getResultList(model.primaryKeyType());
-                        result.addAll(ids);
-                        fireAfterUpsert(batch, ids);
-                    }
-                    case SeqUpdateKey u -> {
-                        List<E> batch = hasEntityCallbacks()
-                                ? partition.chunk().stream().map(this::fireBeforeUpdate).toList()
-                                : partition.chunk();
-                        result.addAll(updateAndFetchIds(batch,
-                                updateQueries.computeIfAbsent(u.fields(), this::prepareUpdateQuery),
-                                entityCache.orElse(null)));
-                    }
-                }
-            });
-            return result;
-        } finally {
-            closeQuietly(updateQueries.values().stream());
-        }
+        return upsertAndFetchIdsPartitioned(entities,
+                (chunk, entityCache) -> upsertPartitionAndFetchIds(chunk, entityCache, this::getUpsertQuery));
     }
 
     private Query getUpsertQuery(Iterable<E> entities) {
@@ -265,77 +90,11 @@ private Query getUpsertQuery(Iterable<E> entities) {
                         .managed());
     }
 
-    @Override
-    protected PreparedQuery prepareUpsertQuery() {
-        var bindVars = ormTemplate.createBindVars();
-        var versionAware = new AtomicBoolean();
-        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () ->
-                ormTemplate.query(flatten(raw("""
-                    INSERT INTO \0
-                    VALUES \0\0""", model.type(), bindVars, onConflictClause(versionAware))))
-                        .managed().prepare());
-    }
-
-    @Override
-    protected void doUpsertBatch(List<E> batch, PreparedQuery query,
-                                 @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return;
-        }
-        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
-            throw new PersistenceException(upsertFailureMessage(batch.size()));
-        }
-    }
-
-    @Override
-    protected List<ID> doUpsertAndFetchIdsBatch(List<E> batch, PreparedQuery query,
-                                                @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return List.of();
-        }
-        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
-            throw new PersistenceException(upsertFailureMessage(batch.size()));
-        }
-        if (isAutoGeneratedPrimaryKey()) {
-            try (var generatedKeys = query.getGeneratedKeys(model.primaryKeyType())) {
-                return generatedKeys.toList();
-            }
-        }
-        return batch.stream().map(Entity::id).toList();
-    }
-
     @Override
     public ID insertAndFetchId(E entity) {
         if (generationStrategy != SEQUENCE) {
             return super.insertAndFetchId(entity);
         }
-        entity = fireBeforeInsert(entity);
-        validateInsert(entity);
-        assert primaryKeyColumns.size() == 1;
-        var primaryKeyColumn = primaryKeyColumns.getFirst();
-        String pkName = primaryKeyColumn.qualifiedName(ormTemplate.dialect());
-        try (var query = ormTemplate.query(TemplateString.raw("""
-                INSERT INTO \0
-                VALUES \0
-                RETURNING %s""".formatted(pkName), model.type(), entity)).managed().prepare()) {
-            ID id = query.getSingleResult(model.primaryKeyType());
-            fireAfterInsert(entity, id);
-            return id;
-        }
+        return insertAndFetchIdReturning(entity);
     }
-
 }
diff --git a/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLSqlDialect.java b/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLSqlDialect.java
index 7b6ff4cee..34b72e199 100644
--- a/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLSqlDialect.java
+++ b/storm-postgresql/src/main/java/st/orm/spi/postgresql/PostgreSQLSqlDialect.java
@@ -27,15 +27,13 @@
 import java.sql.Types;
 import java.util.Set;
 import java.util.UUID;
-import java.util.regex.Pattern;
 import java.util.stream.Stream;
 import st.orm.Operator;
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
 import st.orm.core.spi.JsonString;
-import st.orm.core.template.SqlDialect;
 
-public class PostgreSQLSqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class PostgreSQLSqlDialect extends DefaultSqlDialect {
 
     public PostgreSQLSqlDialect() {
     }
@@ -55,14 +53,6 @@ public String name() {
         return "PostgreSQL";
     }
 
-    /**
-     * PostgreSQL does not support aliasing the target table in DELETE statements.
-     */
-    @Override
-    public boolean supportsDeleteAlias() {
-        return false;
-    }
-
     /**
      * PostgreSQL supports multi-value tuples in the IN clause.
      */
@@ -71,19 +61,6 @@ public boolean supportsMultiValueTuples() {
         return true;
     }
 
-    private static final Pattern POSTGRESQL_IDENTIFIER = Pattern.compile("^[A-Za-z][A-Za-z0-9_]*$");
-
-    /**
-     * Returns the pattern for valid identifiers.
-     *
-     * @return the pattern for valid identifiers.
-     * @since 1.2
-     */
-    @Override
-    public Pattern getValidIdentifierPattern() {
-        return POSTGRESQL_IDENTIFIER;
-    }
-
     private static final Set<String> POSTGRESQL_KEYWORDS = Stream.concat(ANSI_KEYWORDS.stream(), Stream.of(
             "ANALYSE", "BIGSERIAL", "ILIKE", "INDEX", "INITIALLY", "LIMIT", "PLACING",
             "RETURNING", "SERIAL", "SMALLSERIAL", "UNLOGGED", "VARIADIC", "VERBOSE", "WITHIN GROUP", "XML"
@@ -112,40 +89,6 @@ public String escape(String name) {
         return "\"%s\"".formatted(name.replace("\"", "\"\""));
     }
 
-    /**
-     * Regex for double-quoted identifiers (handling doubled double quotes as escapes).
-     */
-    private static final Pattern IDENTIFIER_PATTERN = Pattern.compile(
-            "\"(?:\"\"|[^\"])*\""
-    );
-
-    /**
-     * Returns the pattern for identifiers.
-     *
-     * @return the pattern for identifiers.
-     */
-    @Override
-    public Pattern getIdentifierPattern() {
-        return IDENTIFIER_PATTERN;
-    }
-
-    /**
-     * Regex for single-quoted string literals, handling both doubled single quotes and backslash escapes.
-     */
-    private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile(
-            "'(?:''|\\\\.|[^'\\\\])*'"
-    );
-
-    /**
-     * Returns the pattern for string literals.
-     *
-     * @return the pattern for string literals.
-     */
-    @Override
-    public Pattern getQuoteLiteralPattern() {
-        return QUOTE_LITERAL_PATTERN;
-    }
-
     /**
      * Returns whether a multi-column comparison renders as a row value tuple, which for PostgreSQL is the case for
      * an ordering comparison and for a multi-row list.
@@ -279,16 +222,6 @@ public String forShareLockHint() {
         return "FOR KEY SHARE";
     }
 
-    /**
-     * Returns the lock hint for a write lock.
-     *
-     * @return the lock hint for a write lock.
-     */
-    @Override
-    public String forUpdateLockHint() {
-        return "FOR UPDATE";
-    }
-
     /**
      * Sets a UUID parameter using {@link PreparedStatement#setObject(int, Object)}, which allows the PostgreSQL JDBC
      * driver to bind the value as a native UUID type.
diff --git a/storm-postgresql/src/test/java/st/orm/spi/postgresql/testsupport/TestSpringConnectionProvider.java b/storm-postgresql/src/test/java/st/orm/spi/postgresql/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index 4fd7686ab..000000000
--- a/storm-postgresql/src/test/java/st/orm/spi/postgresql/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.postgresql.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-postgresql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-postgresql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index f5329c1e0..b51953f70 100644
--- a/storm-postgresql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-postgresql/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.postgresql.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.java b/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.java
index 87218d875..e1cd7c2fb 100644
--- a/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.java
+++ b/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormAutoConfiguration.java
@@ -58,8 +58,6 @@
 @EnableConfigurationProperties(StormProperties.class)
 public class StormAutoConfiguration {
 
-    private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(StormAutoConfiguration.class);
-
     /**
      * Creates an {@link ORMTemplate} bean using the provided {@link DataSource} and {@link StormProperties}.
      *
diff --git a/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormRepositoryAutoConfiguration.java b/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormRepositoryAutoConfiguration.java
index 37c2a2c44..387f70210 100644
--- a/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormRepositoryAutoConfiguration.java
+++ b/storm-spring-boot-starter/src/main/java/st/orm/spring/boot/autoconfigure/StormRepositoryAutoConfiguration.java
@@ -20,6 +20,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.annotation.Bean;
 import st.orm.spring.AbstractRepositoryBeanFactoryPostProcessor;
+import st.orm.spring.RepositoryBeanFactoryPostProcessor;
 import st.orm.template.ORMTemplate;
 
 /**
diff --git a/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTestContextCustomizerFactory.java b/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTestContextCustomizerFactory.java
index 0aaf5a37f..6a4fc2320 100644
--- a/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTestContextCustomizerFactory.java
+++ b/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTestContextCustomizerFactory.java
@@ -56,13 +56,13 @@ public void customizeContext(ConfigurableApplicationContext context,
         @Override
         public boolean equals(Object other) {
             return other instanceof DataStormTestContextCustomizer customizer
-                    && Objects.equals(new DataStormTypeExcludeFilter(annotation),
-                                      new DataStormTypeExcludeFilter(customizer.annotation));
+                    && Objects.equals(DataStormTypeExcludeFilter.annotationState(annotation),
+                                      DataStormTypeExcludeFilter.annotationState(customizer.annotation));
         }
 
         @Override
         public int hashCode() {
-            return new DataStormTypeExcludeFilter(annotation).hashCode();
+            return DataStormTypeExcludeFilter.annotationState(annotation).hashCode();
         }
     }
 }
diff --git a/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTypeExcludeFilter.java b/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTypeExcludeFilter.java
index f46988da8..72f83ec3d 100644
--- a/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTypeExcludeFilter.java
+++ b/storm-spring-boot-test-autoconfigure/src/main/java/st/orm/spring/boot/test/DataStormTypeExcludeFilter.java
@@ -113,7 +113,7 @@ public int hashCode() {
         return annotationState(annotation).hashCode();
     }
 
-    private static List<Object> annotationState(DataStormTest annotation) {
+    static List<Object> annotationState(DataStormTest annotation) {
         return List.of(
                 annotation.useDefaultFilters(),
                 Arrays.stream(annotation.includeFilters()).map(AnnotationUtils::getAnnotationAttributes).toList(),
diff --git a/storm-spring/src/main/java/module-info.java b/storm-spring/src/main/java/module-info.java
index 2e9f181b4..a11040c58 100644
--- a/storm-spring/src/main/java/module-info.java
+++ b/storm-spring/src/main/java/module-info.java
@@ -1,3 +1,6 @@
+// The qualified exports below target sibling modules that depend on storm-spring, so they are never
+// observable while storm-spring itself compiles; suppress the resulting "module not found" warnings.
+@SuppressWarnings("module")
 module storm.spring {
     requires static storm.java;
     requires static storm.micrometer;
@@ -27,6 +30,14 @@
     requires java.sql;
     exports st.orm.spring;
     exports st.orm.spring.boot;
-    exports st.orm.spring.impl;
+    // The impl package is reachable by Storm's own modules and by the Spring modules that reflectively
+    // instantiate its auto-configuration, registrar and runtime-hints classes; to everyone else it is not API.
+    exports st.orm.spring.impl to
+            storm.kotlin.spring,
+            spring.beans,
+            spring.boot,
+            spring.boot.autoconfigure,
+            spring.context,
+            spring.core;
     provides st.orm.core.spi.ExternalTransactionProvider with st.orm.spring.SpringExternalTransactionProvider;
 }
diff --git a/storm-spring/src/main/java/st/orm/spring/AbstractRepositoryBeanFactoryPostProcessor.java b/storm-spring/src/main/java/st/orm/spring/AbstractRepositoryBeanFactoryPostProcessor.java
index e7661261d..5e55679b6 100644
--- a/storm-spring/src/main/java/st/orm/spring/AbstractRepositoryBeanFactoryPostProcessor.java
+++ b/storm-spring/src/main/java/st/orm/spring/AbstractRepositoryBeanFactoryPostProcessor.java
@@ -164,11 +164,13 @@ private void registerRepositories(
             Stream<Class<?>> repositories
     ) {
         repositories.forEach(type -> {
+            var factoryBeanClass = getRepositoryFactoryBeanClass();
+            String prefix = getRepositoryPrefix();
             // A FactoryBean definition carrying the repository interface as a constructor argument, rather
             // than an instance supplier: suppliers cannot be processed by Spring AOT into generated code,
             // which would make scanned repositories unavailable in GraalVM native images.
             var definition = (RootBeanDefinition) BeanDefinitionBuilder
-                    .rootBeanDefinition(getRepositoryFactoryBeanClass())
+                    .rootBeanDefinition(factoryBeanClass)
                     .addConstructorArgValue(type)
                     .addConstructorArgValue(getOrmTemplateBeanName())
                     .getBeanDefinition();
@@ -177,9 +179,8 @@ private void registerRepositories(
             // The attribute is not carried into AOT-generated registrations; the target type is, and it
             // binds the FactoryBean's generic to the repository interface so the repository can still be
             // autowired by type in a native image.
-            definition.setTargetType(ResolvableType.forClassWithGenerics(getRepositoryFactoryBeanClass(), type));
-            definition.setAttribute("qualifier", getRepositoryPrefix());
-            String prefix = getRepositoryPrefix();
+            definition.setTargetType(ResolvableType.forClassWithGenerics(factoryBeanClass, type));
+            definition.setAttribute("qualifier", prefix);
             if (prefix != null && !prefix.isEmpty()) {
                 // The qualifier attribute supports autowiring by qualifier on the JVM; the definition-level
                 // qualifier survives AOT processing, where attributes are not carried into generated code.
@@ -188,7 +189,7 @@ private void registerRepositories(
             } else {
                 LOGGER.debug("Registering repository {}.", type.getName());
             }
-            String name = getRepositoryPrefix() + type.getSimpleName();
+            String name = prefix + type.getSimpleName();
             registry.registerBeanDefinition(name, definition);
         });
     }
diff --git a/storm-spring/src/main/java/st/orm/spring/SpringTransactionTemplateProvider.java b/storm-spring/src/main/java/st/orm/spring/SpringTransactionTemplateProvider.java
index 8216ba3a4..8cd29776d 100644
--- a/storm-spring/src/main/java/st/orm/spring/SpringTransactionTemplateProvider.java
+++ b/storm-spring/src/main/java/st/orm/spring/SpringTransactionTemplateProvider.java
@@ -36,11 +36,11 @@
 import st.orm.TransactionPropagation;
 import st.orm.core.spi.CacheRetention;
 import st.orm.core.spi.EntityCache;
-import st.orm.core.spi.EntityCacheImpl;
 import st.orm.core.spi.TransactionContext;
 import st.orm.core.spi.TransactionStatus;
 import st.orm.core.spi.TransactionTemplate;
 import st.orm.core.spi.TransactionTemplateProvider;
+import st.orm.spring.impl.EntityCaches;
 import st.orm.spring.impl.SpringTransactionContext;
 
 /**
@@ -259,16 +259,12 @@ public boolean isRepeatableRead() {
             // The context is bound once per physical Spring transaction, which gives correct cache scoping for
             // REQUIRED and REQUIRES_NEW. NESTED savepoint rollbacks are not observable through Spring's hooks, so no
             // cache splitting is attempted for savepoints.
-            return caches.computeIfAbsent(entityType, ignore -> new EntityCacheImpl<>(retention));
+            return EntityCaches.entityCache(caches, entityType, retention);
         }
 
         @Override
         public EntityCache<? extends Entity<?>, ?> getEntityCache(Class<? extends Entity<?>> entityType) {
-            var cache = caches.get(entityType);
-            if (cache == null) {
-                throw new IllegalStateException("No entity cache exists for " + entityType.getName() + ".");
-            }
-            return cache;
+            return EntityCaches.getEntityCache(caches, entityType);
         }
 
         @Override
@@ -278,9 +274,7 @@ public boolean isRepeatableRead() {
 
         @Override
         public void clearAllEntityCaches() {
-            for (EntityCache<? extends Entity<?>, ?> cache : caches.values()) {
-                cache.clear();
-            }
+            EntityCaches.clearAll(caches);
         }
 
         @Override
diff --git a/storm-spring/src/main/java/st/orm/spring/boot/PerformanceLog.java b/storm-spring/src/main/java/st/orm/spring/boot/PerformanceLog.java
index 0052ec793..7cc1851e8 100644
--- a/storm-spring/src/main/java/st/orm/spring/boot/PerformanceLog.java
+++ b/storm-spring/src/main/java/st/orm/spring/boot/PerformanceLog.java
@@ -18,6 +18,7 @@
 import java.time.Duration;
 import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import st.orm.core.template.SqlLog;
 
 /**
@@ -30,6 +31,9 @@
  */
 final class PerformanceLog {
 
+    /** The logger every boundary reports under. */
+    static final Logger LOGGER = LoggerFactory.getLogger("st.orm.sql.perf");
+
     private PerformanceLog() {
     }
 
@@ -77,14 +81,14 @@ interface Boundary {
      * Returns whether a summary would reach the logger, so a caller can skip opening a scope whose summary
      * nothing consumes.
      */
-    static boolean consumes(Logger logger, Settings settings) {
-        return settings.thresholded() ? logger.isWarnEnabled() : logger.isInfoEnabled();
+    static boolean consumes(Settings settings) {
+        return settings.thresholded() ? LOGGER.isWarnEnabled() : LOGGER.isInfoEnabled();
     }
 
     /**
      * Reports the summary. A unit of work that touched no database says nothing worth a line.
      */
-    static void report(Logger logger, SqlLog.Summary summary, Settings settings) {
+    static void report(SqlLog.Summary summary, Settings settings) {
         if (summary.statementCount() == 0) {
             return;
         }
@@ -93,15 +97,15 @@ static void report(Logger logger, SqlLog.Summary summary, Settings settings) {
         // At TRACE the full statement texts follow the summary, so an elided row can be matched to its
         // statement. TRACE rather than DEBUG because this logger is a child of st.orm.sql: raising that to DEBUG
         // for per-statement logging would otherwise repeat every statement the statement logger already wrote.
-        Object rendered = logger.isTraceEnabled() ? summary.toDetailedString() : summary;
+        Object rendered = LOGGER.isTraceEnabled() ? summary.toDetailedString() : summary;
         if (statementThreshold == null && durationThreshold == null) {
-            logger.info("{}", rendered);
+            LOGGER.info("{}", rendered);
             return;
         }
         boolean exceeded = (statementThreshold != null && summary.statementCount() >= statementThreshold)
                 || (durationThreshold != null && summary.durationNanos() >= durationThreshold.toNanos());
         if (exceeded) {
-            logger.warn("{}", rendered);
+            LOGGER.warn("{}", rendered);
         }
     }
 }
diff --git a/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogEntryPointPostProcessor.java b/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogEntryPointPostProcessor.java
index 27ea76baf..231558ce9 100644
--- a/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogEntryPointPostProcessor.java
+++ b/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogEntryPointPostProcessor.java
@@ -26,7 +26,6 @@
 import org.aopalliance.intercept.MethodInvocation;
 import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.aop.framework.Advised;
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.aop.support.AopUtils;
@@ -59,7 +58,7 @@
 public class StormPerformanceLogEntryPointPostProcessor
         implements BeanPostProcessor, Ordered, PerformanceLog.Boundary {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger("st.orm.sql.perf");
+    private static final Logger LOGGER = PerformanceLog.LOGGER;
 
     private final Set<String> entryPointAnnotations;
 
@@ -179,7 +178,7 @@ public Object invoke(MethodInvocation invocation) throws Throwable {
             // Read once, so a replacement mid-invocation cannot report an invocation against settings it was not
             // recorded under.
             var settings = StormPerformanceLogEntryPointPostProcessor.this.settings;
-            if (!PerformanceLog.consumes(LOGGER, settings)) {
+            if (!PerformanceLog.consumes(settings)) {
                 // Nothing consumes the summary, so do not open a scope to build one.
                 return invocation.proceed();
             }
@@ -189,7 +188,7 @@ public Object invoke(MethodInvocation invocation) throws Throwable {
                 return invocation.proceed();
             } finally {
                 scope.close();
-                PerformanceLog.report(LOGGER, scope.summary(), settings);
+                PerformanceLog.report(scope.summary(), settings);
             }
         }
     }
diff --git a/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogFilter.java b/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogFilter.java
index edd44af7a..08e6aae33 100644
--- a/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogFilter.java
+++ b/storm-spring/src/main/java/st/orm/spring/boot/StormPerformanceLogFilter.java
@@ -22,8 +22,6 @@
 import java.io.IOException;
 import java.time.Duration;
 import org.jspecify.annotations.Nullable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.web.filter.OncePerRequestFilter;
 import st.orm.core.template.SqlLog;
 
@@ -58,8 +56,6 @@
  */
 public class StormPerformanceLogFilter extends OncePerRequestFilter implements PerformanceLog.Boundary {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger("st.orm.sql.perf");
-
     /** Read per request, so a replacement takes effect on the request after it. */
     private volatile PerformanceLog.Settings settings;
 
@@ -120,7 +116,7 @@ protected void doFilterInternal(HttpServletRequest request,
         // Read once, so a replacement mid-request cannot report a request against settings it was not recorded
         // under.
         var settings = this.settings;
-        if (!PerformanceLog.consumes(LOGGER, settings)) {
+        if (!PerformanceLog.consumes(settings)) {
             // Nothing consumes the summary, so do not open a scope to build one.
             chain.doFilter(request, response);
             return;
@@ -130,7 +126,7 @@ protected void doFilterInternal(HttpServletRequest request,
             SqlLog.recordThrowing(name, settings.limit(), settings.callSites(), () -> {
                 chain.doFilter(request, response);
                 return null;
-            }, summary -> PerformanceLog.report(LOGGER, summary, settings));
+            }, summary -> PerformanceLog.report(summary, settings));
         } catch (ServletException | IOException | RuntimeException e) {
             throw e;
         } catch (Exception e) {
diff --git a/storm-spring/src/main/java/st/orm/spring/boot/StormProperties.java b/storm-spring/src/main/java/st/orm/spring/boot/StormProperties.java
index 26b29d8f5..1ec3b0276 100644
--- a/storm-spring/src/main/java/st/orm/spring/boot/StormProperties.java
+++ b/storm-spring/src/main/java/st/orm/spring/boot/StormProperties.java
@@ -248,11 +248,6 @@ public static class Validation {
         public void setStrict(Boolean strict) { this.strict = strict; }
     }
 
-    /**
-     * Maps these properties onto Storm's configuration.
-     *
-     * @since 1.13
-     */
     /** Tracing configuration. */
     public static class Tracing {
 
@@ -284,7 +279,7 @@ public static class SqlLog {
          * that asked for the work rather than the application's own database plumbing. Shared: both logs
          * attribute through the same walker.
          */
-        private List<String> callSiteSkip = java.util.List.of();
+        private List<String> callSiteSkip = List.of();
 
         /** Returns the packages skipped in call-site attribution. */
         public List<String> getCallSiteSkip() { return callSiteSkip; }
@@ -376,7 +371,7 @@ public static class Performance {
              * library is absent from the classpath never matches and costs nothing. Setting the property replaces
              * the default list; an empty list turns entry-point wrapping off.</p>
              */
-            private List<String> entryPoints = java.util.List.of(
+            private List<String> entryPoints = List.of(
                     "org.springframework.scheduling.annotation.Scheduled",
                     "org.springframework.scheduling.annotation.Schedules",
                     "org.springframework.kafka.annotation.KafkaListener",
@@ -498,6 +493,11 @@ public static class ExceptionTranslation {
         public void setEnabled(Boolean enabled) { this.enabled = enabled; }
     }
 
+    /**
+     * Maps these properties onto Storm's configuration.
+     *
+     * @since 1.13
+     */
     public StormConfig toStormConfig() {
         Map<String, String> map = new HashMap<>();
         if (update.getDefaultMode() != null) {
diff --git a/storm-spring/src/main/java/st/orm/spring/impl/EntityCaches.java b/storm-spring/src/main/java/st/orm/spring/impl/EntityCaches.java
new file mode 100644
index 000000000..fd481fc35
--- /dev/null
+++ b/storm-spring/src/main/java/st/orm/spring/impl/EntityCaches.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2024 - 2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package st.orm.spring.impl;
+
+import java.util.Map;
+import st.orm.core.spi.CacheRetention;
+import st.orm.core.spi.EntityCache;
+import st.orm.core.spi.EntityCacheImpl;
+
+/**
+ * The entity-cache bookkeeping shared by the Spring transaction contexts: each context owns one cache map
+ * per physical transaction, keyed by entity type.
+ *
+ * @since 1.14
+ */
+public final class EntityCaches {
+
+    private EntityCaches() {
+    }
+
+    /**
+     * Returns the cache for the entity type, creating it with the given retention on first use.
+     */
+    @SuppressWarnings("unchecked")
+    public static <K extends Class<?>, C extends EntityCache<?, ?>> C entityCache(Map<K, C> caches,
+                                                                                  K entityType,
+                                                                                  CacheRetention retention) {
+        return caches.computeIfAbsent(entityType, ignore -> (C) new EntityCacheImpl<>(retention));
+    }
+
+    /**
+     * Returns the cache for the entity type, failing when none exists.
+     */
+    public static <K extends Class<?>, C extends EntityCache<?, ?>> C getEntityCache(Map<K, C> caches,
+                                                                                     K entityType) {
+        var cache = caches.get(entityType);
+        if (cache == null) {
+            throw new IllegalStateException("No entity cache exists for " + entityType.getName() + ".");
+        }
+        return cache;
+    }
+
+    /**
+     * Clears every cache in the map.
+     */
+    public static void clearAll(Map<?, ? extends EntityCache<?, ?>> caches) {
+        caches.values().forEach(EntityCache::clear);
+    }
+}
diff --git a/storm-spring/src/main/java/st/orm/spring/impl/SpringTransactionContext.java b/storm-spring/src/main/java/st/orm/spring/impl/SpringTransactionContext.java
index 810d78e11..c6d9b99f0 100644
--- a/storm-spring/src/main/java/st/orm/spring/impl/SpringTransactionContext.java
+++ b/storm-spring/src/main/java/st/orm/spring/impl/SpringTransactionContext.java
@@ -58,7 +58,6 @@
 import st.orm.UnexpectedRollbackException;
 import st.orm.core.spi.CacheRetention;
 import st.orm.core.spi.EntityCache;
-import st.orm.core.spi.EntityCacheImpl;
 import st.orm.core.spi.TransactionContext;
 
 /**
@@ -135,6 +134,10 @@ Integer remainingSeconds() {
             long remaining = deadlineNanos - nowNanos();
             return remaining <= 0L ? 0 : (int) (remaining / NANOS_PER_SECOND);
         }
+
+        boolean deadlineExpired() {
+            return deadlineNanos != null && nowNanos() >= deadlineNanos;
+        }
     }
 
     private final Supplier<List<PlatformTransactionManager>> transactionManagers;
@@ -275,18 +278,15 @@ public boolean isRepeatableRead() {
     @Override
     public EntityCache<? extends Entity<?>, ?> entityCache(Class<? extends Entity<?>> entityType,
                                                            CacheRetention retention) {
-        return (EntityCache<? extends Entity<?>, ?>) currentState().entityCacheMap
-                .computeIfAbsent(entityType, ignore -> new EntityCacheImpl<>(retention));
+        return (EntityCache<? extends Entity<?>, ?>) EntityCaches.entityCache(
+                currentState().entityCacheMap, entityType, retention);
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public EntityCache<? extends Entity<?>, ?> getEntityCache(Class<? extends Entity<?>> entityType) {
-        var cache = (EntityCache<? extends Entity<?>, ?>) currentState().entityCacheMap.get(entityType);
-        if (cache == null) {
-            throw new IllegalStateException("No entity cache exists for " + entityType.getName() + ".");
-        }
-        return cache;
+        return (EntityCache<? extends Entity<?>, ?>) EntityCaches.getEntityCache(
+                currentState().entityCacheMap, entityType);
     }
 
     @SuppressWarnings("unchecked")
@@ -301,7 +301,7 @@ public boolean isRepeatableRead() {
      */
     @Override
     public void clearAllEntityCaches() {
-        currentState().entityCacheMap.values().forEach(EntityCache::clear);
+        EntityCaches.clearAll(currentState().entityCacheMap);
     }
 
     @SuppressWarnings("unchecked")
@@ -658,16 +658,14 @@ private static TransactionStatus getTransaction(PlatformTransactionManager trans
 
     private void commit() {
         var current = currentState();
-        boolean expired = current.deadlineNanos != null && nowNanos() >= current.deadlineNanos;
-        if (current.rollbackOnly || expired) {
+        if (current.rollbackOnly || current.deadlineExpired()) {
             rollback();
             return;
         }
         var state = popState();
         // If this frame never touched a DataSource/started a status, still enforce timeout deterministically.
         if (state.transactionStatus == null) {
-            boolean expiredAfter = state.deadlineNanos != null && nowNanos() >= state.deadlineNanos;
-            if (expiredAfter) {
+            if (state.deadlineExpired()) {
                 throw new TransactionTimedOutException(
                         "Transaction did not complete within timeout (" + state.timeoutSeconds + "s).");
             }
@@ -676,8 +674,7 @@ private void commit() {
         try {
             state.transactionManager.commit(state.transactionStatus);
         } catch (org.springframework.transaction.TransactionTimedOutException e) {
-            throw new TransactionTimedOutException(
-                    e.getMessage() == null ? "Did not complete within timeout." : e.getMessage());
+            throw timedOut(e);
         } catch (org.springframework.transaction.UnexpectedRollbackException e) {
             // If Spring threw because some inner joined frame marked rollback-only, surface a clean message.
             throw new UnexpectedRollbackException(
@@ -692,18 +689,13 @@ private void rollback() {
         var state = popState();
         // If the status never started, just check the deadline and throw appropriately.
         if (state.transactionStatus == null) {
-            boolean expired = state.deadlineNanos != null && nowNanos() >= state.deadlineNanos;
-            if (expired) {
-                throw new TransactionTimedOutException(
-                        "Did not complete within timeout (" + state.timeoutSeconds + "s).");
-            }
+            throwIfDeadlineExpired(state);
             return;
         }
         try {
             state.transactionManager.rollback(state.transactionStatus);
         } catch (org.springframework.transaction.TransactionTimedOutException e) {
-            throw new TransactionTimedOutException(
-                    e.getMessage() == null ? "Did not complete within timeout." : e.getMessage());
+            throw timedOut(e);
         } catch (Exception e) {
             throw new PersistenceException(e);
         }
@@ -716,13 +708,22 @@ private void rollback() {
                 outer.entityCacheMap.clear();
             }
         }
-        boolean expired = state.deadlineNanos != null && nowNanos() >= state.deadlineNanos;
-        if (expired) {
+        throwIfDeadlineExpired(state);
+    }
+
+    private static void throwIfDeadlineExpired(TransactionState state) {
+        if (state.deadlineExpired()) {
             throw new TransactionTimedOutException(
                     "Did not complete within timeout (" + state.timeoutSeconds + "s).");
         }
     }
 
+    private static TransactionTimedOutException timedOut(
+            org.springframework.transaction.TransactionTimedOutException e) {
+        return new TransactionTimedOutException(
+                e.getMessage() == null ? "Did not complete within timeout." : e.getMessage());
+    }
+
     private TransactionState popState() {
         if (stack.isEmpty()) {
             throw new IllegalStateException("No transaction in progress to commit/rollback.");
diff --git a/storm-sqlite/pom.xml b/storm-sqlite/pom.xml
index ce5557592..0b30f08e5 100644
--- a/storm-sqlite/pom.xml
+++ b/storm-sqlite/pom.xml
@@ -37,7 +37,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <!-- Run tests on the classpath: the test suite registers a Spring-aware ConnectionProvider via
-                         META-INF/services (see st.orm.spi.sqlite.testsupport), which ServiceLoader only picks up for
+                         META-INF/services (see st.orm.test.spring.TestSpringConnectionProvider), which ServiceLoader only picks up for
                          the unnamed module. This keeps the @Transactional test rollback applying to Storm
                          statements. -->
                     <useModulePath>false</useModulePath>
@@ -101,6 +101,12 @@
             <scope>provided</scope>
         </dependency>
         <!-- Test -->
+        <dependency>
+            <groupId>st.orm</groupId>
+            <artifactId>storm-test</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
diff --git a/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteEntityRepositoryImpl.java b/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteEntityRepositoryImpl.java
index 975d3a5a4..b5d6c5187 100644
--- a/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteEntityRepositoryImpl.java
+++ b/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteEntityRepositoryImpl.java
@@ -15,36 +15,15 @@
  */
 package st.orm.spi.sqlite;
 
-import static java.util.function.Predicate.not;
 import static st.orm.GenerationStrategy.NONE;
-import static st.orm.core.template.SqlInterceptor.intercept;
-import static st.orm.core.template.TemplateString.combine;
 import static st.orm.core.template.TemplateString.raw;
-import static st.orm.core.template.Templates.table;
-import static st.orm.core.template.impl.StringTemplates.flatten;
 
-import java.math.BigInteger;
-import java.sql.Timestamp;
-import java.time.Instant;
-import java.util.Calendar;
-import java.util.Date;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.stream.IntStream;
-import org.jspecify.annotations.Nullable;
-import st.orm.Data;
 import st.orm.Entity;
-import st.orm.NoResultException;
-import st.orm.NonUniqueResultException;
-import st.orm.PersistenceException;
 import st.orm.core.repository.EntityRepository;
-import st.orm.core.repository.impl.EntityRepositoryImpl;
-import st.orm.core.spi.EntityCache;
-import st.orm.core.template.Column;
+import st.orm.core.repository.impl.OnConflictEntityRepositoryImpl;
 import st.orm.core.template.Model;
 import st.orm.core.template.ORMTemplate;
-import st.orm.core.template.PreparedQuery;
-import st.orm.core.template.TemplateString;
 import st.orm.core.template.impl.JoinedEntityHelper;
 
 /**
@@ -54,159 +33,12 @@
  * (available since SQLite 3.24).</p>
  */
 public class SQLiteEntityRepositoryImpl<E extends Entity<ID>, ID>
-        extends EntityRepositoryImpl<E, ID> {
+        extends OnConflictEntityRepositoryImpl<E, ID> {
 
     public SQLiteEntityRepositoryImpl(ORMTemplate ormTemplate, Model<E, ID> model) {
         super(ormTemplate, model);
     }
 
-    private TemplateString getVersionString(Class<? extends Data> type, Column column) {
-        TemplateString columnName = TemplateString.of(column.qualifiedName(ormTemplate.dialect()));
-        TemplateString updateExpression = switch (column.type()) {
-            case Class<?> c when Integer.TYPE.isAssignableFrom(c)
-                    || Long.TYPE.isAssignableFrom(c)
-                    || Integer.class.isAssignableFrom(c)
-                    || Long.class.isAssignableFrom(c)
-                    || BigInteger.class.isAssignableFrom(c) -> raw("\0.\0 + 1", table(type), columnName);
-            case Class<?> c when Instant.class.isAssignableFrom(c)
-                    || Date.class.isAssignableFrom(c)
-                    || Calendar.class.isAssignableFrom(c)
-                    || Timestamp.class.isAssignableFrom(c) -> TemplateString.of(ormTemplate.dialect().currentTimestamp());
-            default ->
-                    throw new PersistenceException("Unsupported version type: %s.".formatted(column.type().getSimpleName()));
-        };
-        return flatten(raw("\0 = \0", columnName, updateExpression));
-    }
-
-    /**
-     * Constructs the SQLite conflict clause for an upsert.
-     *
-     * <p>This method builds an "ON CONFLICT (<primary_keys>) DO UPDATE SET ..." clause.
-     * For non-primary key columns, it assigns the value from the EXCLUDED pseudo-table.
-     * Version columns are updated using {@link #getVersionString(Class, Column)}.</p>
-     *
-     * @param versionAware a flag that will be set if a version column is encountered.
-     * @return the conflict clause as a TemplateString.
-     */
-    private TemplateString onConflictClause(AtomicBoolean versionAware) {
-        var dialect = ormTemplate.dialect();
-        String conflictTarget = model.declaredColumns().stream()
-                .filter(Column::primaryKey)
-                .map(c -> c.qualifiedName(dialect))
-                .reduce("%s, %s"::formatted)
-                .orElseThrow(() -> new PersistenceException("No primary key defined."));
-        var assignments = model.declaredColumns().stream()
-                .filter(not(Column::primaryKey))
-                .filter(Column::updatable)
-                .map(column -> {
-                    if (column.version()) {
-                        versionAware.setPlain(true);
-                        return getVersionString(model.type(), column);
-                    }
-                    return TemplateString.of("%s = EXCLUDED.%s".formatted(column.qualifiedName(dialect), column.qualifiedName(dialect)));
-                })
-                .reduce((left, right) -> combine(left, TemplateString.of(", "), right))
-                .map(st -> combine(TemplateString.of("DO UPDATE SET "), st))
-                .orElse(TemplateString.of("DO NOTHING"));
-        return flatten(combine(TemplateString.of("\nON CONFLICT ("), TemplateString.of(conflictTarget), raw(") \0", assignments)));
-    }
-
-    @Override
-    protected void doUpsert(E entity) {
-        validateUpsert(entity);
-        entityCache().ifPresent(cache -> {
-            if (!model.isDefaultPrimaryKey(entity.id())) {
-                cache.remove(entity.id());
-            }
-        });
-        var versionAware = new AtomicBoolean();
-        intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
-            var query = ormTemplate.query(flatten(raw("""
-                    INSERT INTO \0
-                    VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed();
-            query.executeUpdate();
-        });
-    }
-
-    @Override
-    protected ID doUpsertAndFetchId(E entity) {
-        validateUpsert(entity);
-        entityCache().ifPresent(cache -> {
-            if (!model.isDefaultPrimaryKey(entity.id())) {
-                cache.remove(entity.id());
-            }
-        });
-        var versionAware = new AtomicBoolean();
-        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () -> {
-            try (var query = ormTemplate.query(flatten(raw("""
-                        INSERT INTO \0
-                        VALUES \0\0""", model.type(), entity, onConflictClause(versionAware)))).managed().prepare()) {
-                query.executeUpdate();
-                if (isAutoGeneratedPrimaryKey()) {
-                    try (var stream = query.getGeneratedKeys(model.primaryKeyType())) {
-                        return stream.reduce((ignore1, ignore2) -> {
-                            throw new NonUniqueResultException("Expected single result, but found more than one.");
-                        }).orElseThrow(() -> new NoResultException("Expected single result, but found none."));
-                    }
-                }
-                return entity.id();
-            }
-        });
-    }
-
-    @Override
-    protected PreparedQuery prepareUpsertQuery() {
-        var bindVars = ormTemplate.createBindVars();
-        var versionAware = new AtomicBoolean();
-        return intercept(sql -> sql.versionAware(versionAware.getPlain()), () ->
-                ormTemplate.query(flatten(raw("""
-                    INSERT INTO \0
-                    VALUES \0\0""", model.type(), bindVars, onConflictClause(versionAware))))
-                        .managed().prepare());
-    }
-
-    @Override
-    protected void doUpsertBatch(List<E> batch, PreparedQuery query,
-                                 @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return;
-        }
-        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
-            throw new PersistenceException(upsertFailureMessage(batch.size()));
-        }
-    }
-
-    @Override
-    protected List<ID> doUpsertAndFetchIdsBatch(List<E> batch, PreparedQuery query,
-                                                @Nullable EntityCache<E, ID> cache) {
-        if (batch.isEmpty()) {
-            return List.of();
-        }
-        batch.stream().map(this::validateUpsert).forEach(query::addBatch);
-        if (cache != null) {
-            batch.stream()
-                    .filter(e -> !model.isDefaultPrimaryKey(e.id()))
-                    .forEach(e -> cache.remove(e.id()));
-        }
-        int[] result = query.executeBatch();
-        if (IntStream.of(result).anyMatch(r -> r != 0 && r != 1 && r != 2)) {
-            throw new PersistenceException(upsertFailureMessage(batch.size()));
-        }
-        if (isAutoGeneratedPrimaryKey()) {
-            try (var generatedKeys = query.getGeneratedKeys(model.primaryKeyType())) {
-                return generatedKeys.toList();
-            }
-        }
-        return batch.stream().map(Entity::id).toList();
-    }
-
     /**
      * Overrides joined entity batch insert to use SQLite's {@code RETURNING} clause instead of
      * {@code executeBatch()} followed by {@code getGeneratedKeys()}, which the SQLite JDBC driver
@@ -237,10 +69,4 @@ protected List<ID> insertJoinedBatch(List<E> entities) {
         JoinedEntityHelper.insertExtensionTables(ormTemplate, model, entities, ids);
         return ids;
     }
-
-    @Override
-    public ID insertAndFetchId(E entity) {
-        // SQLite does not support sequences.
-        return super.insertAndFetchId(entity);
-    }
 }
diff --git a/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteSqlDialect.java b/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteSqlDialect.java
index 4d03cf38b..010a703d3 100644
--- a/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteSqlDialect.java
+++ b/storm-sqlite/src/main/java/st/orm/spi/sqlite/SQLiteSqlDialect.java
@@ -29,9 +29,8 @@
 import st.orm.PersistenceException;
 import st.orm.StormConfig;
 import st.orm.core.spi.DefaultSqlDialect;
-import st.orm.core.template.SqlDialect;
 
-public class SQLiteSqlDialect extends DefaultSqlDialect implements SqlDialect {
+public class SQLiteSqlDialect extends DefaultSqlDialect {
 
     public SQLiteSqlDialect() {
     }
@@ -51,22 +50,6 @@ public String name() {
         return "SQLite";
     }
 
-    /**
-     * SQLite does not support aliasing the target table in DELETE statements.
-     */
-    @Override
-    public boolean supportsDeleteAlias() {
-        return false;
-    }
-
-    /**
-     * SQLite does not support multi-value tuples in the IN clause.
-     */
-    @Override
-    public boolean supportsMultiValueTuples() {
-        return false;
-    }
-
     private static final Pattern SQLITE_IDENTIFIER = Pattern.compile("^[A-Za-z_][A-Za-z0-9_]*$");
 
     /**
@@ -111,24 +94,7 @@ public String escape(String name) {
     }
 
     /**
-     * Regex for double-quoted identifiers (handling doubled double quotes as escapes).
-     */
-    private static final Pattern IDENTIFIER_PATTERN = Pattern.compile(
-            "\"(?:\"\"|[^\"])*\""
-    );
-
-    /**
-     * Returns the pattern for identifiers.
-     *
-     * @return the pattern for identifiers.
-     */
-    @Override
-    public Pattern getIdentifierPattern() {
-        return IDENTIFIER_PATTERN;
-    }
-
-    /**
-     * Regex for single-quoted string literals, handling both doubled single quotes and backslash escapes.
+     * Regex for single-quoted string literals, handling doubled single quotes as escapes.
      */
     private static final Pattern QUOTE_LITERAL_PATTERN = Pattern.compile(
             "'(?:''|[^'])*'"
diff --git a/storm-sqlite/src/test/java/st/orm/spi/sqlite/testsupport/TestSpringConnectionProvider.java b/storm-sqlite/src/test/java/st/orm/spi/sqlite/testsupport/TestSpringConnectionProvider.java
deleted file mode 100644
index e883c923b..000000000
--- a/storm-sqlite/src/test/java/st/orm/spi/sqlite/testsupport/TestSpringConnectionProvider.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2024 - 2026 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package st.orm.spi.sqlite.testsupport;
-
-import java.sql.Connection;
-import javax.sql.DataSource;
-import org.jspecify.annotations.Nullable;
-import org.springframework.jdbc.datasource.DataSourceUtils;
-import st.orm.PersistenceException;
-import st.orm.core.spi.ConnectionProvider;
-import st.orm.core.spi.Orderable.BeforeAny;
-import st.orm.core.spi.TransactionContext;
-
-/**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
- * transaction-per-test isolation applies to statements executed by Storm templates.
- */
-@BeforeAny
-public class TestSpringConnectionProvider implements ConnectionProvider {
-
-    @Override
-    public Connection getConnection(DataSource dataSource, @Nullable TransactionContext context) {
-        try {
-            return DataSourceUtils.getConnection(dataSource);
-        } catch (Exception e) {
-            throw new PersistenceException("Failed to get connection from DataSource.", e);
-        }
-    }
-
-    @Override
-    public void releaseConnection(Connection connection, DataSource dataSource, @Nullable TransactionContext context) {
-        DataSourceUtils.releaseConnection(connection, dataSource);
-    }
-}
diff --git a/storm-sqlite/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider b/storm-sqlite/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
index 268e99aa1..b51953f70 100644
--- a/storm-sqlite/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
+++ b/storm-sqlite/src/test/resources/META-INF/services/st.orm.core.spi.ConnectionProvider
@@ -1 +1 @@
-st.orm.spi.sqlite.testsupport.TestSpringConnectionProvider
+st.orm.test.spring.TestSpringConnectionProvider
diff --git a/storm-test/pom.xml b/storm-test/pom.xml
index d840c2042..5ebb49a97 100644
--- a/storm-test/pom.xml
+++ b/storm-test/pom.xml
@@ -123,6 +123,13 @@
             <artifactId>h2</artifactId>
             <scope>provided</scope>
         </dependency>
+        <!-- Spring sits behind the Spring-aware test support in st.orm.test.spring: only suites that bind
+             Storm statements to Spring-managed test transactions bring it. -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-jdbc</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <!-- Testcontainers sits behind StormTest.database(): tests bring the module of the database they run on,
              and tests on H2 bring nothing, so the module compiles against the core in provided scope. -->
         <dependency>
diff --git a/storm-test/src/main/java/module-info.java b/storm-test/src/main/java/module-info.java
index 4944e493a..e1735a333 100644
--- a/storm-test/src/main/java/module-info.java
+++ b/storm-test/src/main/java/module-info.java
@@ -1,7 +1,10 @@
 module storm.test {
+    // st.orm.test.spring is deliberately not exported: the suites that use it run on the classpath, where the
+    // ServiceLoader registration in their test resources picks it up; it is not API.
     exports st.orm.test;
     requires storm.core;
     requires static org.junit.jupiter.api;
+    requires static spring.jdbc;
     requires java.sql;
     requires java.logging;
     requires static org.jspecify;
diff --git a/storm-test/src/main/java/st/orm/test/SqlCapture.java b/storm-test/src/main/java/st/orm/test/SqlCapture.java
index 5f4481b3e..9f1b626fd 100644
--- a/storm-test/src/main/java/st/orm/test/SqlCapture.java
+++ b/storm-test/src/main/java/st/orm/test/SqlCapture.java
@@ -200,9 +200,7 @@ public int count() {
      * @return the matching statement count.
      */
     public int count(Operation operation) {
-        return (int) statements.stream()
-                .filter(s -> s.operation() == operation)
-                .count();
+        return statements(operation).size();
     }
 
     /**
@@ -216,9 +214,7 @@ public int count(Operation operation) {
      * @since 1.13
      */
     public int count(Origin origin) {
-        return (int) statements.stream()
-                .filter(s -> s.origin() == origin)
-                .count();
+        return statements(origin).size();
     }
 
     /**
diff --git a/storm-h2/src/test/java/st/orm/spi/h2/testsupport/TestSpringConnectionProvider.java b/storm-test/src/main/java/st/orm/test/spring/TestSpringConnectionProvider.java
similarity index 85%
rename from storm-h2/src/test/java/st/orm/spi/h2/testsupport/TestSpringConnectionProvider.java
rename to storm-test/src/main/java/st/orm/test/spring/TestSpringConnectionProvider.java
index e78bb859a..4c8889ec3 100644
--- a/storm-h2/src/test/java/st/orm/spi/h2/testsupport/TestSpringConnectionProvider.java
+++ b/storm-test/src/main/java/st/orm/test/spring/TestSpringConnectionProvider.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package st.orm.spi.h2.testsupport;
+package st.orm.test.spring;
 
 import java.sql.Connection;
 import javax.sql.DataSource;
@@ -25,8 +25,11 @@
 import st.orm.core.spi.TransactionContext;
 
 /**
- * Test-only connection provider that binds connections to Spring's transaction management, so the test suite's
+ * Test-only connection provider that binds connections to Spring's transaction management, so a test suite's
  * transaction-per-test isolation applies to statements executed by Storm templates.
+ *
+ * <p>A test suite registers this provider through {@code META-INF/services} on the test classpath; the
+ * production integration configures {@code SpringConnectionProvider} on the template builder instead.</p>
  */
 @BeforeAny
 public class TestSpringConnectionProvider implements ConnectionProvider {