From cf5214bf7bbcd815a4493333da58afdf500ed00d Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 31 Oct 2025 13:51:01 -0400 Subject: [PATCH] Don't reset the pathlist of partitioned joinrels. Adjust the regression tests to suppress the failures, except for one problematic case, which fails with this patch applied. --- src/backend/optimizer/plan/planner.c | 4 +- src/test/regress/expected/partition_join.out | 44 +++++++++++--------- src/test/regress/expected/subselect.out | 43 +++++++------------ src/test/regress/sql/partition_join.sql | 16 +++++-- src/test/regress/sql/subselect.sql | 2 + 5 files changed, 57 insertions(+), 52 deletions(-) diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index c4fd646b999..f4d8d89e7e2 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -7924,7 +7924,7 @@ apply_scanjoin_target_to_paths(PlannerInfo *root, * generate_useful_gather_paths to add path(s) to the main list, and * finally zap the partial pathlist. */ - if (rel_is_partitioned) + if (rel_is_partitioned && IS_SIMPLE_REL(rel)) rel->pathlist = NIL; /* @@ -7950,7 +7950,7 @@ apply_scanjoin_target_to_paths(PlannerInfo *root, } /* Finish dropping old paths for a partitioned rel, per comment above */ - if (rel_is_partitioned) + if (rel_is_partitioned && IS_SIMPLE_REL(rel)) rel->partial_pathlist = NIL; /* Extract SRF-free scan/join target. */ diff --git a/src/test/regress/expected/partition_join.out b/src/test/regress/expected/partition_join.out index 713828be335..4e363ea3792 100644 --- a/src/test/regress/expected/partition_join.out +++ b/src/test/regress/expected/partition_join.out @@ -63,18 +63,21 @@ SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.b AND t1.b = (4 rows) -- inner join with partially-redundant join clauses +-- (avoid a mergejoin, because the planner thinks that an non-partitionwise +-- merge join is the cheapest plan, and we want to test a partitionwise join) +BEGIN; +SET LOCAL enable_mergejoin = false; EXPLAIN (COSTS OFF) SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = t2.b ORDER BY t1.a, t2.b; - QUERY PLAN ---------------------------------------------------------------- + QUERY PLAN +-------------------------------------------------- Sort Sort Key: t1.a -> Append - -> Merge Join - Merge Cond: (t1_1.a = t2_1.a) - -> Index Scan using iprt1_p1_a on prt1_p1 t1_1 - -> Sort - Sort Key: t2_1.b + -> Hash Join + Hash Cond: (t1_1.a = t2_1.a) + -> Seq Scan on prt1_p1 t1_1 + -> Hash -> Seq Scan on prt2_p1 t2_1 Filter: (a = b) -> Hash Join @@ -89,7 +92,7 @@ SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = -> Hash -> Seq Scan on prt2_p3 t2_3 Filter: (a = b) -(22 rows) +(21 rows) SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = t2.b ORDER BY t1.a, t2.b; a | c | b | c @@ -101,6 +104,7 @@ SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = 24 | 0024 | 24 | 0024 (5 rows) +COMMIT; -- left outer join, 3-way EXPLAIN (COSTS OFF) SELECT COUNT(*) FROM prt1 t1 @@ -1244,11 +1248,12 @@ SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN ( 450 | 0 | 0450 (4 rows) --- test merge joins +-- test merge joins, slightly modifying the query to ensure that we still +-- get a fully partitionwise join SET enable_hashjoin TO off; SET enable_nestloop TO off; EXPLAIN (COSTS OFF) -SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; +SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) ORDER BY t1.a; QUERY PLAN ------------------------------------------------------------------ Merge Append @@ -1258,7 +1263,6 @@ SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN ( -> Sort Sort Key: t1_3.a -> Seq Scan on prt1_p1 t1_3 - Filter: (b = 0) -> Merge Semi Join Merge Cond: (t1_6.b = (((t1_9.a + t1_9.b) / 2))) -> Sort @@ -1273,7 +1277,6 @@ SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN ( -> Sort Sort Key: t1_4.a -> Seq Scan on prt1_p2 t1_4 - Filter: (b = 0) -> Merge Semi Join Merge Cond: (t1_7.b = (((t1_10.a + t1_10.b) / 2))) -> Sort @@ -1288,7 +1291,6 @@ SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN ( -> Sort Sort Key: t1_5.a -> Seq Scan on prt1_p3 t1_5 - Filter: (b = 0) -> Merge Semi Join Merge Cond: (t1_8.b = (((t1_11.a + t1_11.b) / 2))) -> Sort @@ -1298,9 +1300,9 @@ SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN ( Sort Key: (((t1_11.a + t1_11.b) / 2)) -> Seq Scan on prt1_e_p3 t1_11 Filter: (c = 0) -(47 rows) +(44 rows) -SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; +SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) ORDER BY t1.a; a | b | c -----+---+------ 0 | 0 | 0000 @@ -5233,8 +5235,11 @@ CREATE TABLE fract_t1 PARTITION OF fract_t FOR VALUES FROM ('1000') TO ('2000'); INSERT INTO fract_t (id) (SELECT generate_series(0, 1999)); ANALYZE fract_t; -- verify plan; nested index only scans +-- (avoid merge joins, because the costs of partitionwise and non-partitionwise +-- merge joins tend to be almost equal, and we want this test to be stable) SET max_parallel_workers_per_gather = 0; SET enable_partitionwise_join = on; +SET enable_mergejoin = off; EXPLAIN (COSTS OFF) SELECT x.id, y.id FROM fract_t x LEFT JOIN fract_t y USING (id) ORDER BY x.id ASC LIMIT 10; QUERY PLAN @@ -5242,14 +5247,14 @@ SELECT x.id, y.id FROM fract_t x LEFT JOIN fract_t y USING (id) ORDER BY x.id AS Limit -> Merge Append Sort Key: x.id - -> Merge Left Join - Merge Cond: (x_1.id = y_1.id) + -> Nested Loop Left Join -> Index Only Scan using fract_t0_pkey on fract_t0 x_1 -> Index Only Scan using fract_t0_pkey on fract_t0 y_1 - -> Merge Left Join - Merge Cond: (x_2.id = y_2.id) + Index Cond: (id = x_1.id) + -> Nested Loop Left Join -> Index Only Scan using fract_t1_pkey on fract_t1 x_2 -> Index Only Scan using fract_t1_pkey on fract_t1 y_2 + Index Cond: (id = x_2.id) (11 rows) EXPLAIN (COSTS OFF) @@ -5366,6 +5371,7 @@ EXPLAIN (COSTS OFF) SELECT * FROM pht1 p1 JOIN pht1 p2 USING (c) LIMIT 1000; -> Seq Scan on pht1_p3 p2_3 (17 rows) +RESET enable_mergejoin; SET max_parallel_workers_per_gather = 1; SET debug_parallel_query = on; -- Partial paths should also be smart enough to employ limits diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out index cf6b32d1173..774c22b6e3a 100644 --- a/src/test/regress/expected/subselect.out +++ b/src/test/regress/expected/subselect.out @@ -844,16 +844,19 @@ create index on unique_tbl_p3(a); analyze unique_tbl_p; set enable_partitionwise_join to on; -- Ensure that the unique-ification works for partition-wise join +-- (Only one of the two joins will be done partitionwise, but that's good +-- enough for our purposes.) explain (verbose, costs off) select * from unique_tbl_p t1, unique_tbl_p t2 where (t1.a, t2.a) in (select a, a from unique_tbl_p t3) order by t1.a, t2.a; QUERY PLAN ------------------------------------------------------------------------------------------------ - Merge Append - Sort Key: t1.a - -> Nested Loop - Output: t1_1.a, t1_1.b, t2_1.a, t2_1.b + Merge Join + Output: t1.a, t1.b, t2.a, t2.b + Merge Cond: (t1.a = t2.a) + -> Merge Append + Sort Key: t1.a -> Nested Loop Output: t1_1.a, t1_1.b, t3_1.a -> Unique @@ -863,15 +866,6 @@ order by t1.a, t2.a; -> Index Scan using unique_tbl_p1_a_idx on public.unique_tbl_p1 t1_1 Output: t1_1.a, t1_1.b Index Cond: (t1_1.a = t3_1.a) - -> Memoize - Output: t2_1.a, t2_1.b - Cache Key: t1_1.a - Cache Mode: logical - -> Index Scan using unique_tbl_p1_a_idx on public.unique_tbl_p1 t2_1 - Output: t2_1.a, t2_1.b - Index Cond: (t2_1.a = t1_1.a) - -> Nested Loop - Output: t1_2.a, t1_2.b, t2_2.a, t2_2.b -> Nested Loop Output: t1_2.a, t1_2.b, t3_2.a -> Unique @@ -881,15 +875,6 @@ order by t1.a, t2.a; -> Index Scan using unique_tbl_p2_a_idx on public.unique_tbl_p2 t1_2 Output: t1_2.a, t1_2.b Index Cond: (t1_2.a = t3_2.a) - -> Memoize - Output: t2_2.a, t2_2.b - Cache Key: t1_2.a - Cache Mode: logical - -> Index Scan using unique_tbl_p2_a_idx on public.unique_tbl_p2 t2_2 - Output: t2_2.a, t2_2.b - Index Cond: (t2_2.a = t1_2.a) - -> Nested Loop - Output: t1_3.a, t1_3.b, t2_3.a, t2_3.b -> Nested Loop Output: t1_3.a, t1_3.b, t3_3.a -> Unique @@ -902,14 +887,16 @@ order by t1.a, t2.a; -> Index Scan using unique_tbl_p3_a_idx on public.unique_tbl_p3 t1_3 Output: t1_3.a, t1_3.b Index Cond: (t1_3.a = t3_3.a) - -> Memoize - Output: t2_3.a, t2_3.b - Cache Key: t1_3.a - Cache Mode: logical + -> Materialize + Output: t2.a, t2.b + -> Append + -> Index Scan using unique_tbl_p1_a_idx on public.unique_tbl_p1 t2_1 + Output: t2_1.a, t2_1.b + -> Index Scan using unique_tbl_p2_a_idx on public.unique_tbl_p2 t2_2 + Output: t2_2.a, t2_2.b -> Index Scan using unique_tbl_p3_a_idx on public.unique_tbl_p3 t2_3 Output: t2_3.a, t2_3.b - Index Cond: (t2_3.a = t1_3.a) -(59 rows) +(44 rows) reset enable_partitionwise_join; drop table unique_tbl_p; diff --git a/src/test/regress/sql/partition_join.sql b/src/test/regress/sql/partition_join.sql index 30f15ee9acb..9c958da270d 100644 --- a/src/test/regress/sql/partition_join.sql +++ b/src/test/regress/sql/partition_join.sql @@ -35,9 +35,14 @@ SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.b AND t1.b = SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.b AND t1.b = 0 ORDER BY t1.a, t2.b; -- inner join with partially-redundant join clauses +-- (avoid a mergejoin, because the planner thinks that an non-partitionwise +-- merge join is the cheapest plan, and we want to test a partitionwise join) +BEGIN; +SET LOCAL enable_mergejoin = false; EXPLAIN (COSTS OFF) SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = t2.b ORDER BY t1.a, t2.b; SELECT t1.a, t1.c, t2.b, t2.c FROM prt1 t1, prt2 t2 WHERE t1.a = t2.a AND t1.a = t2.b ORDER BY t1.a, t2.b; +COMMIT; -- left outer join, 3-way EXPLAIN (COSTS OFF) @@ -219,13 +224,14 @@ EXPLAIN (COSTS OFF) SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; --- test merge joins +-- test merge joins, slightly modifying the query to ensure that we still +-- get a fully partitionwise join SET enable_hashjoin TO off; SET enable_nestloop TO off; EXPLAIN (COSTS OFF) -SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; -SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) AND t1.b = 0 ORDER BY t1.a; +SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) ORDER BY t1.a; +SELECT t1.* FROM prt1 t1 WHERE t1.a IN (SELECT t1.b FROM prt2 t1 WHERE t1.b IN (SELECT (t1.a + t1.b)/2 FROM prt1_e t1 WHERE t1.c = 0)) ORDER BY t1.a; EXPLAIN (COSTS OFF) SELECT t1.a, t1.c, t2.b, t2.c, t3.a + t3.b, t3.c FROM (prt1 t1 LEFT JOIN prt2 t2 ON t1.a = t2.b) RIGHT JOIN prt1_e t3 ON (t1.a = (t3.a + t3.b)/2) WHERE t3.c = 0 ORDER BY t1.a, t2.b, t3.a + t3.b; @@ -1216,8 +1222,11 @@ INSERT INTO fract_t (id) (SELECT generate_series(0, 1999)); ANALYZE fract_t; -- verify plan; nested index only scans +-- (avoid merge joins, because the costs of partitionwise and non-partitionwise +-- merge joins tend to be almost equal, and we want this test to be stable) SET max_parallel_workers_per_gather = 0; SET enable_partitionwise_join = on; +SET enable_mergejoin = off; EXPLAIN (COSTS OFF) SELECT x.id, y.id FROM fract_t x LEFT JOIN fract_t y USING (id) ORDER BY x.id ASC LIMIT 10; @@ -1240,6 +1249,7 @@ EXPLAIN (COSTS OFF) SELECT * FROM pht1 p1 JOIN pht1 p2 USING (c) LIMIT 100; -- If almost all the data should be fetched - prefer SeqScan EXPLAIN (COSTS OFF) SELECT * FROM pht1 p1 JOIN pht1 p2 USING (c) LIMIT 1000; +RESET enable_mergejoin; SET max_parallel_workers_per_gather = 1; SET debug_parallel_query = on; -- Partial paths should also be smart enough to employ limits diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql index 36a8a0aa1d5..7b4ebff46d8 100644 --- a/src/test/regress/sql/subselect.sql +++ b/src/test/regress/sql/subselect.sql @@ -419,6 +419,8 @@ analyze unique_tbl_p; set enable_partitionwise_join to on; -- Ensure that the unique-ification works for partition-wise join +-- (Only one of the two joins will be done partitionwise, but that's good +-- enough for our purposes.) explain (verbose, costs off) select * from unique_tbl_p t1, unique_tbl_p t2 where (t1.a, t2.a) in (select a, a from unique_tbl_p t3) -- 2.39.3 (Apple Git-145)