Update test cases

src/backend/distributed/planner/query_pushdown_planning.c

@@ -1722,22 +1722,20 @@ DeferredErrorIfUnsupportedLateralSubquery(PlannerInfo *plannerInfo,
 	return NULL;
 }
 
- /*
+
-  * ContainsLateralSubquery checks if the given plannerInfo contains any
+/*
-  * lateral subqueries in its rtable. If it does, it returns true, otherwise false.
+ * ContainsLateralSubquery checks if the given plannerInfo contains any
-  */
+ * lateral subqueries in its rtable. If it does, it returns true, otherwise false.
+ */
 static bool
 ContainsLateralSubquery(PlannerInfo *plannerInfo)
 {
 	ListCell *lc;
-	int rteIndex = 0;
 
 	foreach(lc, plannerInfo->parse->rtable)
 	{
 		RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
 
-		rteIndex++;
-
 		/* We are only interested in subqueries that are lateral */
 		if (rte->lateral && rte->rtekind == RTE_SUBQUERY)
 		{

src/backend/distributed/planner/recursive_planning.c

@@ -754,7 +754,6 @@ RecursivelyPlanRecurringTupleOuterJoinWalker(Node *node, Query *query,
 			case JOIN_LEFT:
 			{
 				/* <recurring> left join <distributed> */
-
 				if (leftNodeRecurs && !rightNodeRecurs)
 				{
 					if (chainedJoin || !CheckPushDownFeasibilityLeftJoin(joinExpr, query))

src/test/regress/expected/recurring_outer_join.out

@@ -1808,19 +1808,17 @@ BEGIN;
       SELECT t1.a, t1.b FROM ref_1 t1
       LEFT JOIN
       (
-          SELECT * FROM dist_1 t2 WHERE EXISTS (
+          SELECT DISTINCT ON (a) * FROM dist_1 t2 WHERE EXISTS (
               SELECT * FROM dist_1 t4
               WHERE t4.a = t2.a
-          )
+          ) ORDER BY a, b
       ) t3
       USING (a)
   ) q
   WHERE dist_5.a = q.a
   RETURNING *;
-DEBUG:  recursively planning right side of the left join since the outer side is a recurring rel
+DEBUG:  generating subplan XXX_1 for subquery SELECT t1.a, t1.b FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT DISTINCT ON (t2.a) t2.a, t2.b FROM recurring_outer_join.dist_1 t2 WHERE (EXISTS (SELECT t4.a, t4.b FROM recurring_outer_join.dist_1 t4 WHERE (t4.a OPERATOR(pg_catalog.=) t2.a))) ORDER BY t2.a, t2.b) t3 USING (a))
-DEBUG:  recursively planning the distributed subquery since it is part of a distributed join node that is outer joined with a recurring rel
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: DELETE FROM recurring_outer_join.dist_5 USING (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) q WHERE (dist_5.a OPERATOR(pg_catalog.=) q.a) RETURNING dist_5.a, dist_5.b, q.a, q.b
-DEBUG:  generating subplan XXX_1 for subquery SELECT a, b FROM recurring_outer_join.dist_1 t2 WHERE (EXISTS (SELECT t4.a, t4.b FROM recurring_outer_join.dist_1 t4 WHERE (t4.a OPERATOR(pg_catalog.=) t2.a)))
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: DELETE FROM recurring_outer_join.dist_5 USING (SELECT t1.a, t1.b FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) t3 USING (a))) q WHERE (dist_5.a OPERATOR(pg_catalog.=) q.a) RETURNING dist_5.a, dist_5.b, q.a, q.b
  a | b  | a |  b
 ---------------------------------------------------------------------
  1 | 10 | 1 |  11
@@ -1848,10 +1846,8 @@ BEGIN;
     USING (a)
   )
   RETURNING *;
-DEBUG:  recursively planning right side of the left join since the outer side is a recurring rel
+DEBUG:  generating subplan XXX_1 for subquery SELECT t1.a FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT t2.a, t2.b FROM recurring_outer_join.dist_1 t2 WHERE (EXISTS (SELECT t4.a, t4.b FROM recurring_outer_join.dist_1 t4 WHERE (t4.a OPERATOR(pg_catalog.=) t2.a)))) t3 USING (a))
-DEBUG:  recursively planning the distributed subquery since it is part of a distributed join node that is outer joined with a recurring rel
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: UPDATE recurring_outer_join.dist_5 SET b = 10 WHERE (a OPERATOR(pg_catalog.=) ANY (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer))) RETURNING a, b
-DEBUG:  generating subplan XXX_1 for subquery SELECT a, b FROM recurring_outer_join.dist_1 t2 WHERE (EXISTS (SELECT t4.a, t4.b FROM recurring_outer_join.dist_1 t4 WHERE (t4.a OPERATOR(pg_catalog.=) t2.a)))
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: UPDATE recurring_outer_join.dist_5 SET b = 10 WHERE (a OPERATOR(pg_catalog.=) ANY (SELECT t1.a FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) t3 USING (a)))) RETURNING a, b
  a | b
 ---------------------------------------------------------------------
  1 | 10
@@ -1864,7 +1860,7 @@ DEBUG:  Plan XXX query after replacing subqueries and CTEs: UPDATE recurring_out
 (7 rows)
 
 ROLLBACK;
--- INSERT .. SELECT: pull to coordinator
+-- INSERT .. SELECT: Repartitioned
 BEGIN;
   DELETE FROM ref_1 WHERE a IS NULL;
   INSERT INTO dist_1
@@ -1872,12 +1868,25 @@ BEGIN;
   FROM ref_1 t1
   LEFT JOIN dist_1 t2
   ON (t1.a = t2.a);
-DEBUG:  cannot perform a lateral outer join when a distributed subquery references a reference table
+DEBUG:  cannot perform distributed INSERT INTO ... SELECT because the partition columns in the source table and subquery do not match
+DETAIL:  The target table's partition column should correspond to a partition column in the subquery.
+DEBUG:  performing repartitioned INSERT ... SELECT
+ROLLBACK;
+-- INSERT .. SELECT: pull to coordinator
+BEGIN;
+  DELETE FROM ref_1 WHERE a IS NULL;
+  INSERT INTO dist_1
+  SELECT t1.*
+  FROM ref_1 t1
+  LEFT JOIN dist_1 t2
+  ON (t1.b = t2.b);
+DEBUG:  cannot perform distributed INSERT INTO ... SELECT because the partition columns in the source table and subquery do not match
+DETAIL:  The target table's partition column should correspond to a partition column in the subquery.
 DEBUG:  recursively planning right side of the left join since the outer side is a recurring rel
 DEBUG:  recursively planning distributed relation "dist_1" "t2" since it is part of a distributed join node that is outer joined with a recurring rel
 DEBUG:  Wrapping relation "dist_1" "t2" to a subquery
-DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM recurring_outer_join.dist_1 t2 WHERE true
+DEBUG:  generating subplan XXX_1 for subquery SELECT b FROM recurring_outer_join.dist_1 t2 WHERE true
-DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT t1.a, t1.b FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT t2_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) t2_1) t2 ON ((t1.a OPERATOR(pg_catalog.=) t2.a)))
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT t1.a, t1.b FROM (recurring_outer_join.ref_1 t1 LEFT JOIN (SELECT NULL::integer AS a, t2_1.b FROM (SELECT intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(b integer)) t2_1) t2 ON ((t1.b OPERATOR(pg_catalog.=) t2.b)))
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
 ROLLBACK;
 -- INSERT .. SELECT: repartitioned (due to <t1.a*3>)

src/test/regress/sql/recurring_outer_join.sql

@@ -956,10 +956,10 @@ BEGIN;
       SELECT t1.a, t1.b FROM ref_1 t1
       LEFT JOIN
       (
-          SELECT * FROM dist_1 t2 WHERE EXISTS (
+          SELECT DISTINCT ON (a) * FROM dist_1 t2 WHERE EXISTS (
               SELECT * FROM dist_1 t4
               WHERE t4.a = t2.a
-          )
+          ) ORDER BY a, b
       ) t3
       USING (a)
   ) q
@@ -984,7 +984,7 @@ BEGIN;
   RETURNING *;
 ROLLBACK;
 
--- INSERT .. SELECT: pull to coordinator
+-- INSERT .. SELECT: Repartitioned
 BEGIN;
   DELETE FROM ref_1 WHERE a IS NULL;
 
@@ -995,6 +995,17 @@ BEGIN;
   ON (t1.a = t2.a);
 ROLLBACK;
 
+-- INSERT .. SELECT: pull to coordinator
+BEGIN;
+  DELETE FROM ref_1 WHERE a IS NULL;
+
+  INSERT INTO dist_1
+  SELECT t1.*
+  FROM ref_1 t1
+  LEFT JOIN dist_1 t2
+  ON (t1.b = t2.b);
+ROLLBACK;
+
 -- INSERT .. SELECT: repartitioned (due to <t1.a*3>)
 BEGIN;
   INSERT INTO dist_1