FIXME: It looks like PostgreSQL planner pruning feature does not work properly

The partition_pruning test stated GP6 introduced the pruning issue. Please refer the commit 3ea5477 to solve the pruning bug in PostgreSQL planner.

Author: Tao-Ma

src/test/regress/expected/partition_pruning.out

@@ -38,9 +38,9 @@ explain select * from parttab where length(n::text) = 3;
 ---------------------------------------------------------------------------------
  Gather Motion 3:1  (slice1; segments: 3)  (cost=0.00..533.04 rows=70 width=64)
    ->  Append  (cost=0.00..532.12 rows=23 width=64)
-         ->  Seq Scan on parttab_1_prt_one  (cost=0.00..266.00 rows=12 width=64)
+         ->  Seq Scan on parttab_1_prt_one parttab_1  (cost=0.00..266.00 rows=12 width=64)
                Filter: (length((n)::text) = 3)
-         ->  Seq Scan on parttab_1_prt_two  (cost=0.00..266.00 rows=12 width=64)
+         ->  Seq Scan on parttab_1_prt_two parttab_2  (cost=0.00..266.00 rows=12 width=64)
                Filter: (length((n)::text) = 3)
  Optimizer: Postgres query optimizer
 (7 rows)

src/test/regress/expected/qp_dropped_cols.out

@@ -14977,30 +14977,30 @@ EXPLAIN (costs off) SELECT * FROM ds_main, non_part2 WHERE ds_main.c = non_part2
                                             QUERY PLAN                                             
 ---------------------------------------------------------------------------------------------------
  Gather Motion 3:1  (slice1; segments: 3)
-   Merge Key: ds_main_1_prt_2.a
+   Merge Key: ds_main.a
    ->  Sort
-         Sort Key: ds_main_1_prt_2.a
+         Sort Key: ds_main.a
          ->  HashAggregate
                Group Key: (RowIdExpr)
                ->  Redistribute Motion 3:3  (slice2; segments: 3)
                      Hash Key: (RowIdExpr)
                      ->  Nested Loop
                            ->  Broadcast Motion 3:3  (slice3; segments: 3)
                                  ->  Hash Join
-                                       Hash Cond: (ds_main_1_prt_2.c = non_part2.e)
+                                       Hash Cond: (ds_main.c = non_part2.e)
                                        ->  Append
                                              Partition Selectors: $0
-                                             ->  Seq Scan on ds_main_1_prt_2
+                                             ->  Seq Scan on ds_main_1_prt_2 ds_main_1
                                                    Filter: (a IS NOT NULL)
-                                             ->  Seq Scan on ds_main_1_prt_3
+                                             ->  Seq Scan on ds_main_1_prt_3 ds_main_2
                                                    Filter: (a IS NOT NULL)
-                                             ->  Seq Scan on ds_main_1_prt_4
+                                             ->  Seq Scan on ds_main_1_prt_4 ds_main_3
                                                    Filter: (a IS NOT NULL)
-                                             ->  Seq Scan on ds_main_1_prt_5
+                                             ->  Seq Scan on ds_main_1_prt_5 ds_main_4
                                                    Filter: (a IS NOT NULL)
-                                             ->  Seq Scan on ds_main_1_prt_6
+                                             ->  Seq Scan on ds_main_1_prt_6 ds_main_5
                                                    Filter: (a IS NOT NULL)
-                                             ->  Seq Scan on ds_main_1_prt_deflt
+                                             ->  Seq Scan on ds_main_1_prt_deflt ds_main_6
                                                    Filter: (a IS NOT NULL)
                                        ->  Hash
                                              ->  Partition Selector (selector id: $0)