2 files changed, 33 insertions, 0 deletions
diff --git a/src/test/regress/expected/select_distinct.out b/src/test/regress/expected/select_distinct.out
index 9d44ea8056d..1f72756ccb4 100644
--- a/src/test/regress/expected/select_distinct.out
+++ b/src/test/regress/expected/select_distinct.out
@@ -348,6 +348,26 @@ SELECT DISTINCT four,1,2,3 FROM tenk1 WHERE four = 0;
     0 |        1 |        2 |        3
 (1 row)
 
+SET parallel_setup_cost=0;
+SET min_parallel_table_scan_size=0;
+SET max_parallel_workers_per_gather=2;
+-- Ensure we get a plan with a Limit 1 in both partial distinct and final
+-- distinct
+EXPLAIN (COSTS OFF)
+SELECT DISTINCT four FROM tenk1 WHERE four = 10;
+                  QUERY PLAN                  
+----------------------------------------------
+ Limit
+   ->  Gather
+         Workers Planned: 2
+         ->  Limit
+               ->  Parallel Seq Scan on tenk1
+                     Filter: (four = 10)
+(6 rows)
+
+RESET max_parallel_workers_per_gather;
+RESET min_parallel_table_scan_size;
+RESET parallel_setup_cost;
 --
 -- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
 -- very own regression file.
diff --git a/src/test/regress/sql/select_distinct.sql b/src/test/regress/sql/select_distinct.sql
index 1643526d991..da92c197aba 100644
--- a/src/test/regress/sql/select_distinct.sql
+++ b/src/test/regress/sql/select_distinct.sql
@@ -180,6 +180,19 @@ SELECT DISTINCT four,1,2,3 FROM tenk1 WHERE four = 0;
 -- Ensure we only get 1 row
 SELECT DISTINCT four,1,2,3 FROM tenk1 WHERE four = 0;
 
+SET parallel_setup_cost=0;
+SET min_parallel_table_scan_size=0;
+SET max_parallel_workers_per_gather=2;
+
+-- Ensure we get a plan with a Limit 1 in both partial distinct and final
+-- distinct
+EXPLAIN (COSTS OFF)
+SELECT DISTINCT four FROM tenk1 WHERE four = 10;
+
+RESET max_parallel_workers_per_gather;
+RESET min_parallel_table_scan_size;
+RESET parallel_setup_cost;
+
 --
 -- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
 -- very own regression file.