enable idx lookup join by default in tests (#28439) (#28737)

Author: gridnevvvit

ydb/core/kqp/opt/kqp_query_plan.cpp

@@ -2304,7 +2304,9 @@ class TQueryPlanReconstructor {
             lookupOps.AppendValue(std::move(lookupOp));
             lookupPlan["Operators"] = std::move(lookupOps);
 
-            newPlans.AppendValue(ReconstructImpl(plan.GetMapSafe().at("Plans").GetArraySafe()[0], 0));
+	        if (plan.GetMapSafe().contains("Plans")) {
+                newPlans.AppendValue(ReconstructImpl(plan.GetMapSafe().at("Plans").GetArraySafe()[0], 0));
+            }
 
             newPlans.AppendValue(std::move(lookupPlan));
 

ydb/core/kqp/ut/join/kqp_join_ut.cpp

@@ -653,7 +653,10 @@ Y_UNIT_TEST_SUITE(KqpJoin) {
     }
 
      Y_UNIT_TEST(LeftJoinPushdownPredicate_NestedJoin) {
-        TKikimrRunner kikimr;
+        TKikimrSettings appsettings;
+        appsettings.AppConfig.MutableTableServiceConfig()->SetEnableKqpDataQueryStreamIdxLookupJoin(true);
+
+        TKikimrRunner kikimr(appsettings);
         auto db = kikimr.GetTableClient();
         auto session = db.CreateSession().GetValueSync().GetSession();
 
@@ -671,7 +674,8 @@ Y_UNIT_TEST_SUITE(KqpJoin) {
                 INNER JOIN `/Root/Join1_3` AS t3
                 ON t1.Fk1 = t3.Key
 
-                WHERE t2.Value > 1001;
+                WHERE t2.Value > 1001
+
             )"), TTxControl::BeginTx().CommitTx()).ExtractValueSync();
             UNIT_ASSERT_C(result.IsSuccess(), result.GetIssues().ToString());
             CompareYson(
@@ -694,7 +698,8 @@ Y_UNIT_TEST_SUITE(KqpJoin) {
                 LEFT JOIN `/Root/Join1_2` AS t2
                 ON t1.Fk1 = t2.Key
 
-                WHERE t2.Value > 1001;
+                WHERE t2.Value > 1001
+                ORDER BY t1.Key1, t1.Key2;
             )"), TTxControl::BeginTx().CommitTx()).ExtractValueSync();
             UNIT_ASSERT_C(result.IsSuccess(), result.GetIssues().ToString());
             CompareYson(

ydb/tests/functional/canonical/canondata/test_sql.TestCanonicalFolder1.test_case_join_group_by_lookup.script-script_/join_group_by_lookup.script.plan

@@ -19,7 +19,10 @@
                 },
                 {
                     "columns": [
-                        "Key"
+                        "Fk21",
+                        "Fk22",
+                        "Key",
+                        "Value"
                     ],
                     "lookup_by": [
                         "Key"