Preserve partitioning on temp FILE_LOADS tables

sdks/python/apache_beam/io/gcp/bigquery_file_loads.py

@@ -82,6 +82,32 @@
 _SLEEP_DURATION_BETWEEN_POLLS = 10
 
 
+def _has_partitioning_load_parameters(additional_parameters):
+  return (
+      'timePartitioning' in additional_parameters or
+      'rangePartitioning' in additional_parameters)
+
+
+def _add_destination_partitioning_load_parameters(
+    additional_parameters, destination_table):
+  if destination_table is None:
+    return additional_parameters
+
+  additional_parameters = dict(additional_parameters)
+  time_partitioning = getattr(destination_table, 'timePartitioning', None)
+  range_partitioning = getattr(destination_table, 'rangePartitioning', None)
+
+  if ('timePartitioning' not in additional_parameters and
+      isinstance(time_partitioning, bigquery_tools.bigquery.TimePartitioning)):
+    additional_parameters['timePartitioning'] = time_partitioning
+
+  if ('rangePartitioning' not in additional_parameters and isinstance(
+      range_partitioning, bigquery_tools.bigquery.RangePartitioning)):
+    additional_parameters['rangePartitioning'] = range_partitioning
+
+  return additional_parameters
+
+
 def _generate_job_name(job_name, job_type, step_name):
   return bigquery_tools.generate_bq_job_name(
       job_name=job_name,
@@ -688,6 +714,7 @@ def start_bundle(self):
       self.bq_io_metadata = create_bigquery_io_metadata(self._step_name)
     self.pending_jobs = []
     self.schema_cache = {}
+    self.destination_table_cache = {}
 
   def process(
       self,
@@ -716,6 +743,7 @@ def process(
       additional_parameters = self.additional_bq_parameters.get()
     else:
       additional_parameters = self.additional_bq_parameters
+    additional_parameters = dict(additional_parameters or {})
 
     table_reference = bigquery_tools.parse_table_reference(destination)
     if table_reference.projectId is None:
@@ -735,28 +763,55 @@ def process(
 
     create_disposition = self.create_disposition
     if self.temporary_tables:
+      destination_table = None
+      hashed_dest = bigquery_tools.get_hashable_destination(table_reference)
+      need_schema = schema is None and hashed_dest not in self.schema_cache
+      need_partitioning = not _has_partitioning_load_parameters(
+          additional_parameters)
+      if need_schema or need_partitioning:
+        try:
+          if hashed_dest in self.destination_table_cache:
+            destination_table = self.destination_table_cache[hashed_dest]
+          else:
+            destination_table = self.bq_wrapper.get_table(
+                project_id=table_reference.projectId,
+                dataset_id=table_reference.datasetId,
+                table_id=table_reference.tableId)
+            self.destination_table_cache[hashed_dest] = destination_table
+        except Exception as e:
+          if need_schema:
+            _LOGGER.warning(
+                "Input schema is absent and could not fetch the final "
+                "destination table's schema [%s]. Creating temp table [%s] "
+                "will likely fail: %s",
+                hashed_dest,
+                job_name,
+                e)
+          destination_table = None
+
       # we need to create temp tables, so we need a schema.
       # if there is no input schema, fetch the destination table's schema
       if schema is None:
-        hashed_dest = bigquery_tools.get_hashable_destination(table_reference)
         if hashed_dest in self.schema_cache:
           schema = self.schema_cache[hashed_dest]
-        else:
-          try:
-            schema = bigquery_tools.table_schema_to_dict(
-                bigquery_tools.BigQueryWrapper().get_table(
-                    project_id=table_reference.projectId,
-                    dataset_id=table_reference.datasetId,
-                    table_id=table_reference.tableId).schema)
+        elif destination_table is not None:
+          destination_schema = getattr(destination_table, 'schema', None)
+          if isinstance(destination_schema,
+                        bigquery_tools.bigquery.TableSchema):
+            schema = bigquery_tools.table_schema_to_dict(destination_schema)
             self.schema_cache[hashed_dest] = schema
-          except Exception as e:
+          else:
             _LOGGER.warning(
-                "Input schema is absent and could not fetch the final "
-                "destination table's schema [%s]. Creating temp table [%s] "
-                "will likely fail: %s",
+                "Input schema is absent and the final destination table [%s] "
+                "does not have a usable schema. Creating temp table [%s] will "
+                "likely fail.",
                 hashed_dest,
-                job_name,
-                e)
+                job_name)
+
+      if (destination_table is not None and
+          not _has_partitioning_load_parameters(additional_parameters)):
+        additional_parameters = _add_destination_partitioning_load_parameters(
+            additional_parameters, destination_table)
 
       # If we are using temporary tables, then we must always create the
       # temporary tables, so we replace the create_disposition.

sdks/python/apache_beam/io/gcp/bigquery_file_loads_test.py

@@ -703,6 +703,157 @@ def test_one_load_job_failed_after_waiting(self, sleep_mock):
 
     sleep_mock.assert_called_once()
 
+  def test_temporary_table_load_inherits_destination_time_partitioning(self):
+    destination = 'project1:dataset1.table1'
+    partition = (destination, (0, ['gs://bucket/file1']))
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+    destination_table = bigquery_api.Table(
+        timePartitioning=bigquery_api.TimePartitioning(type='DAY'))
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=_ELEMENTS_SCHEMA, test_client=mock.Mock(), temporary_tables=True)
+    dofn.start_bundle()
+    dofn.bq_wrapper.get_table = mock.Mock(return_value=destination_table)
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(dofn.process(partition, 'test_job', pane_info=mock.Mock(index=0)))
+
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertEqual(
+        load_call['additional_load_parameters']['timePartitioning'],
+        destination_table.timePartitioning)
+    dofn.bq_wrapper.get_table.assert_called_once_with(
+        project_id='project1', dataset_id='dataset1', table_id='table1')
+
+  def test_temporary_table_load_inherits_destination_range_partitioning(self):
+    destination = 'project1:dataset1.table1'
+    partition = (destination, (0, ['gs://bucket/file1']))
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+    destination_table = bigquery_api.Table(
+        rangePartitioning=bigquery_api.RangePartitioning())
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=_ELEMENTS_SCHEMA, test_client=mock.Mock(), temporary_tables=True)
+    dofn.start_bundle()
+    dofn.bq_wrapper.get_table = mock.Mock(return_value=destination_table)
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(dofn.process(partition, 'test_job', pane_info=mock.Mock(index=0)))
+
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertEqual(
+        load_call['additional_load_parameters']['rangePartitioning'],
+        destination_table.rangePartitioning)
+    dofn.bq_wrapper.get_table.assert_called_once_with(
+        project_id='project1', dataset_id='dataset1', table_id='table1')
+
+  def test_temporary_table_load_keeps_explicit_partitioning_parameters(self):
+    destination = 'project1:dataset1.table1'
+    partition = (destination, (0, ['gs://bucket/file1']))
+    explicit_partitioning = {'timePartitioning': {'type': 'DAY'}}
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=_ELEMENTS_SCHEMA,
+        test_client=mock.Mock(),
+        temporary_tables=True,
+        additional_bq_parameters=explicit_partitioning)
+    dofn.start_bundle()
+    dofn.bq_wrapper.get_table = mock.Mock()
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(dofn.process(partition, 'test_job', pane_info=mock.Mock(index=0)))
+
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertEqual(
+        load_call['additional_load_parameters'], explicit_partitioning)
+    dofn.bq_wrapper.get_table.assert_not_called()
+
+  def test_temporary_table_load_uses_cached_schema_with_explicit_partitioning(
+      self):
+    destination = 'project1:dataset1.table1'
+    partition = (destination, (0, ['gs://bucket/file1']))
+    explicit_partitioning = {'timePartitioning': {'type': 'DAY'}}
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+    table_reference = bigquery_tools.parse_table_reference(destination)
+    hashed_dest = bigquery_tools.get_hashable_destination(table_reference)
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=None,
+        test_client=mock.Mock(),
+        temporary_tables=True,
+        additional_bq_parameters=explicit_partitioning)
+    dofn.start_bundle()
+    dofn.schema_cache[hashed_dest] = _ELEMENTS_SCHEMA
+    dofn.bq_wrapper.get_table = mock.Mock()
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(dofn.process(partition, 'test_job', pane_info=mock.Mock(index=0)))
+
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertEqual(load_call['schema'], _ELEMENTS_SCHEMA)
+    self.assertEqual(
+        load_call['additional_load_parameters'], explicit_partitioning)
+    dofn.bq_wrapper.get_table.assert_not_called()
+
+  def test_temporary_table_load_caches_destination_table_per_bundle(self):
+    destination = 'project1:dataset1.table1'
+    first_partition = (destination, (0, ['gs://bucket/file1']))
+    second_partition = (destination, (1, ['gs://bucket/file2']))
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+    destination_table = bigquery_api.Table(
+        timePartitioning=bigquery_api.TimePartitioning(type='DAY'))
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=_ELEMENTS_SCHEMA, test_client=mock.Mock(), temporary_tables=True)
+    dofn.start_bundle()
+    dofn.bq_wrapper.get_table = mock.Mock(return_value=destination_table)
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(
+        dofn.process(first_partition, 'test_job', pane_info=mock.Mock(index=0)))
+    list(
+        dofn.process(
+            second_partition, 'test_job', pane_info=mock.Mock(index=1)))
+
+    dofn.bq_wrapper.get_table.assert_called_once_with(
+        project_id='project1', dataset_id='dataset1', table_id='table1')
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertEqual(
+        load_call['additional_load_parameters']['timePartitioning'],
+        destination_table.timePartitioning)
+
+  def test_temporary_table_load_ignores_invalid_mock_partitioning_metadata(
+      self):
+    destination = 'project1:dataset1.table1'
+    partition = (destination, (0, ['gs://bucket/file1']))
+    job_reference = bigquery_api.JobReference(
+        projectId='project1', jobId='job_name1')
+    destination_table = mock.Mock()
+    destination_table.timePartitioning = mock.Mock()
+    destination_table.rangePartitioning = mock.Mock()
+
+    dofn = bqfl.TriggerLoadJobs(
+        schema=_ELEMENTS_SCHEMA, test_client=mock.Mock(), temporary_tables=True)
+    dofn.start_bundle()
+    dofn.bq_wrapper.get_table = mock.Mock(return_value=destination_table)
+    dofn.bq_wrapper.perform_load_job = mock.Mock(return_value=job_reference)
+
+    list(dofn.process(partition, 'test_job', pane_info=mock.Mock(index=0)))
+
+    load_call = dofn.bq_wrapper.perform_load_job.call_args.kwargs
+    self.assertNotIn(
+        'timePartitioning', load_call['additional_load_parameters'])
+    self.assertNotIn(
+        'rangePartitioning', load_call['additional_load_parameters'])
+    dofn.bq_wrapper.get_table.assert_called_once_with(
+        project_id='project1', dataset_id='dataset1', table_id='table1')
+
   def test_multiple_partition_files(self):
     destination = 'project1:dataset1.table1'
 

sdks/python/apache_beam/io/gcp/bigquery_write_it_test.py

@@ -42,6 +42,7 @@
 from apache_beam.io.gcp.bigquery_tools import BigQueryWrapper
 from apache_beam.io.gcp.bigquery_tools import FileFormat
 from apache_beam.io.gcp.internal.clients import bigquery
+from apache_beam.io.gcp.tests.bigquery_matcher import BigQueryTableMatcher
 from apache_beam.io.gcp.tests.bigquery_matcher import BigqueryFullResultMatcher
 from apache_beam.testing.test_pipeline import TestPipeline
 from apache_beam.testing.util import assert_that
@@ -87,7 +88,7 @@ def tearDown(self):
           self.dataset_id,
           self.project)
 
-  def create_table(self, table_name):
+  def create_table(self, table_name, time_partitioning=None):
     table_schema = bigquery.TableSchema()
     table_field = bigquery.TableFieldSchema()
     table_field.name = 'int64'
@@ -112,6 +113,8 @@ def create_table(self, table_name):
             datasetId=self.dataset_id,
             tableId=table_name),
         schema=table_schema)
+    if time_partitioning is not None:
+      table.timePartitioning = time_partitioning
     request = bigquery.BigqueryTablesInsertRequest(
         projectId=self.project, datasetId=self.dataset_id, table=table)
     self.bigquery_client.client.tables.Insert(request)
@@ -377,6 +380,72 @@ def test_big_query_write_without_schema(self):
               write_disposition=beam.io.BigQueryDisposition.WRITE_APPEND,
               temp_file_format=FileFormat.JSON))
 
+  @pytest.mark.it_postcommit
+  @mock.patch(
+      "apache_beam.io.gcp.bigquery_file_loads._MAXIMUM_SOURCE_URIS", new=1)
+  @retry(reraise=True, stop=stop_after_attempt(3))
+  def test_big_query_file_loads_existing_partitioned_table(self):
+    table_name = 'python_file_loads_partitioned_table'
+    self.create_table(
+        table_name,
+        time_partitioning=bigquery.TimePartitioning(field='date', type='DAY'))
+    table_id = '{}.{}'.format(self.dataset_id, table_name)
+
+    input_data = [{
+        'int64': 1, 'bytes': b'abc', 'date': '2026-01-01', 'time': '00:00:00'
+    },
+                  {
+                      'int64': 2,
+                      'bytes': b'xyz',
+                      'date': '2026-01-02',
+                      'time': '12:34:56'
+                  }]
+    for row in input_data:
+      row['bytes'] = base64.b64encode(row['bytes'])
+
+    args = self.test_pipeline.get_full_options_as_args(
+        on_success_matcher=hc.all_of(
+            BigqueryFullResultMatcher(
+                project=self.project,
+                query=(
+                    "SELECT int64, bytes, date, time FROM %s ORDER BY int64" %
+                    table_id),
+                data=[
+                    (
+                        1,
+                        b'abc',
+                        datetime.date(2026, 1, 1),
+                        datetime.time(0, 0, 0),
+                    ),
+                    (
+                        2,
+                        b'xyz',
+                        datetime.date(2026, 1, 2),
+                        datetime.time(12, 34, 56),
+                    ),
+                ]),
+            BigQueryTableMatcher(
+                project=self.project,
+                dataset=self.dataset_id,
+                table=table_name,
+                expected_properties={
+                    'timePartitioning': {
+                        'field': 'date',
+                        'type': 'DAY',
+                    }
+                })))
+
+    with beam.Pipeline(argv=args) as p:
+      # pylint: disable=expression-not-assigned
+      (
+          p | 'create' >> beam.Create(input_data)
+          | 'write' >> beam.io.WriteToBigQuery(
+              table_id,
+              write_disposition=beam.io.BigQueryDisposition.WRITE_APPEND,
+              max_file_size=1,  # bytes
+              method=beam.io.WriteToBigQuery.Method.FILE_LOADS,
+              temp_file_format=FileFormat.JSON))
+
   @pytest.mark.it_postcommit
   def test_big_query_write_insert_errors_reporting(self):
     """