Update multi_insert_select_conflict

src/test/regress/expected/multi_insert_select_conflict.out

@@ -274,8 +274,9 @@ DEBUG:  generating subplan XXX_1 for CTE basic: SELECT col_1, col_2 FROM on_conf
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT col_1, col_2 FROM (SELECT basic.col_1, basic.col_2 FROM (SELECT intermediate_result.col_1, intermediate_result.col_2 FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(col_1 integer, col_2 integer)) basic) citus_insert_select_subquery
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
 RESET client_min_messages;
--- Following query is not supported since error checks of the subquery pushdown planner
--- and insert select planner have not been unified. It should work after unifying them.
+-- Following query is supported by using repartition join for the insert/select
+SELECT coordinator_plan($Q$
+EXPLAIN (costs off)
 WITH cte AS (
 	SELECT
 		col_1, col_2
@@ -288,8 +289,17 @@ SELECT
 	source_table_1.col_2
 FROM cte, source_table_1
 WHERE cte.col_1 = source_table_1.col_1 ON CONFLICT DO NOTHING;
-ERROR:  cannot perform distributed planning for the given modification
-DETAIL:  Select query cannot be pushed down to the worker.
+$Q$);
+                coordinator_plan
+---------------------------------------------------------------------
+ Custom Scan (Citus INSERT ... SELECT)
+   INSERT/SELECT method: repartition
+   ->  Custom Scan (Citus Adaptive)
+         ->  Distributed Subplan XXX_1
+               ->  Custom Scan (Citus Adaptive)
+                     Task Count: 4
+(6 rows)
+
 SET citus.enable_cte_inlining TO true;
 -- Tests with foreign key to reference table
 CREATE TABLE test_ref_table (key int PRIMARY KEY);

src/test/regress/sql/multi_insert_select_conflict.sql

@@ -153,8 +153,9 @@ UPDATE target_table SET col_2 = 4 WHERE col_1 IN (SELECT col_1 FROM cte);
 
 RESET client_min_messages;
 
--- Following query is not supported since error checks of the subquery pushdown planner
--- and insert select planner have not been unified. It should work after unifying them.
+-- Following query is supported by using repartition join for the insert/select
+SELECT coordinator_plan($Q$
+EXPLAIN (costs off)
 WITH cte AS (
 	SELECT
 		col_1, col_2
@@ -167,6 +168,7 @@ SELECT
 	source_table_1.col_2
 FROM cte, source_table_1
 WHERE cte.col_1 = source_table_1.col_1 ON CONFLICT DO NOTHING;
+$Q$);
 
 SET citus.enable_cte_inlining TO true;