From ccf9f6cfe2a8078961ce2250ec56884ac12b6e01 Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Thu, 31 Oct 2024 21:58:30 +0900 Subject: [PATCH v3 2/2] Disallow partitionwise join when collation doesn't match Insist that the collation used for joining matches exactly with the collation used for partitioning to allow using partitionwise join. Reported-by: Tender Wang Author: Jian He Author: Amit Langote Reviewed-by: Tender Wang Reviewed-by: Junwang Zhao Discussion: https://postgr.es/m/18568-2a9afb6b9f7e6ed3@postgresql.org Discussion: https://postgr.es/m/tencent_9D9103CDA420C07768349CC1DFF88465F90A@qq.com Discussion: https://postgr.es/m/CAHewXNno_HKiQ6PqyLYfuqDtwp7KKHZiH1J7Pqyz0nr+PS2Dwg@mail.gmail.com --- src/backend/optimizer/util/relnode.c | 26 +++++- .../regress/expected/collate.icu.utf8.out | 89 +++++++++++++++++++ src/test/regress/sql/collate.icu.utf8.sql | 17 ++++ 3 files changed, 130 insertions(+), 2 deletions(-) diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c index d7266e4cdb..0dfcd3a556 100644 --- a/src/backend/optimizer/util/relnode.c +++ b/src/backend/optimizer/util/relnode.c @@ -2258,6 +2258,8 @@ have_partkey_equi_join(PlannerInfo *root, RelOptInfo *joinrel, { Node *expr1 = (Node *) lfirst(lc); ListCell *lc2; + Oid partcoll1 = rel1->part_scheme->partcollation[ipk]; + Oid exprcoll1 = exprCollation(expr1); foreach(lc2, rel2->partexprs[ipk]) { @@ -2265,8 +2267,18 @@ have_partkey_equi_join(PlannerInfo *root, RelOptInfo *joinrel, if (exprs_known_equal(root, expr1, expr2, btree_opfamily)) { - pk_known_equal[ipk] = true; - break; + Oid partcoll2 = rel1->part_scheme->partcollation[ipk]; + Oid exprcoll2 = exprCollation(expr2); + + /* + * Ensure that the collations match those of the partition + * keys. + */ + if (partcoll1 == exprcoll1 && partcoll2 == exprcoll2) + { + pk_known_equal[ipk] = true; + break; + } } } if (pk_known_equal[ipk]) @@ -2301,6 +2313,7 @@ static int match_expr_to_partition_keys(Expr *expr, RelOptInfo *rel, bool strict_op) { int cnt; + Oid exprcoll = exprCollation((Node *) expr); /* This function should be called only for partitioned relations. */ Assert(rel->part_scheme); @@ -2314,10 +2327,15 @@ match_expr_to_partition_keys(Expr *expr, RelOptInfo *rel, bool strict_op) for (cnt = 0; cnt < rel->part_scheme->partnatts; cnt++) { ListCell *lc; + Oid partcoll = rel->part_scheme->partcollation[cnt]; /* We can always match to the non-nullable partition keys. */ foreach(lc, rel->partexprs[cnt]) { + if (OidIsValid(partcoll) && OidIsValid(exprcoll) && + partcoll != exprcoll) + return -1; + if (equal(lfirst(lc), expr)) return cnt; } @@ -2334,6 +2352,10 @@ match_expr_to_partition_keys(Expr *expr, RelOptInfo *rel, bool strict_op) */ foreach(lc, rel->nullable_partexprs[cnt]) { + if (OidIsValid(partcoll) && OidIsValid(exprcoll) && + partcoll != exprcoll) + return -1; + if (equal(lfirst(lc), expr)) return cnt; } diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out index 3d6d8f9a20..56239737cd 100644 --- a/src/test/regress/expected/collate.icu.utf8.out +++ b/src/test/regress/expected/collate.icu.utf8.out @@ -2136,6 +2136,95 @@ SELECT c collate "C", count(c) FROM pagg_tab3 GROUP BY c collate "C" ORDER BY 1; b | 2 (4 rows) +-- Partitionwise join should not be allowed too when the collation used by the +-- join keys doesn't match the partition key +SET enable_partitionwise_join TO false; +EXPLAIN (COSTS OFF) +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + QUERY PLAN +------------------------------------------------------------- + Sort + Sort Key: t1.c COLLATE case_insensitive + -> HashAggregate + Group Key: t1.c + -> Hash Join + Hash Cond: (t1.c = t2.c) + -> Append + -> Seq Scan on pagg_tab3_p2 t1_1 + -> Seq Scan on pagg_tab3_p1 t1_2 + -> Hash + -> Append + -> Seq Scan on pagg_tab3_p2 t2_1 + -> Seq Scan on pagg_tab3_p1 t2_2 +(13 rows) + +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + c | count +---+------- + A | 16 + B | 16 +(2 rows) + +SET enable_partitionwise_join TO true; +EXPLAIN (COSTS OFF) +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + QUERY PLAN +------------------------------------------------------------- + Sort + Sort Key: t1.c COLLATE case_insensitive + -> HashAggregate + Group Key: t1.c + -> Hash Join + Hash Cond: (t1.c = t2.c) + -> Append + -> Seq Scan on pagg_tab3_p2 t1_1 + -> Seq Scan on pagg_tab3_p1 t1_2 + -> Hash + -> Append + -> Seq Scan on pagg_tab3_p2 t2_1 + -> Seq Scan on pagg_tab3_p1 t2_2 +(13 rows) + +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + c | count +---+------- + A | 16 + B | 16 +(2 rows) + +-- OK when the join key uses the same collation. +EXPLAIN (COSTS OFF) +SELECT t1.c COLLATE "C", count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c COLLATE "C" GROUP BY t1.c COLLATE "C" ORDER BY 1; + QUERY PLAN +------------------------------------------------------------------ + Sort + Sort Key: ((t1.c)::text) COLLATE "C" + -> Append + -> HashAggregate + Group Key: (t1.c)::text + -> Hash Join + Hash Cond: ((t1.c)::text = (t2.c)::text) + -> Seq Scan on pagg_tab3_p2 t1 + -> Hash + -> Seq Scan on pagg_tab3_p2 t2 + -> HashAggregate + Group Key: (t1_1.c)::text + -> Hash Join + Hash Cond: ((t1_1.c)::text = (t2_1.c)::text) + -> Seq Scan on pagg_tab3_p1 t1_1 + -> Hash + -> Seq Scan on pagg_tab3_p1 t2_1 +(17 rows) + +SELECT t1.c COLLATE "C", count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c COLLATE "C" GROUP BY t1.c COLLATE "C" ORDER BY 1; + c | count +---+------- + A | 4 + B | 4 + a | 4 + b | 4 +(4 rows) + RESET enable_partitionwise_aggregate; RESET max_parallel_workers_per_gather; RESET enable_incremental_sort; diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql index eaf9a99be7..b5f872742b 100644 --- a/src/test/regress/sql/collate.icu.utf8.sql +++ b/src/test/regress/sql/collate.icu.utf8.sql @@ -828,6 +828,23 @@ EXPLAIN (COSTS OFF) SELECT c collate "C", count(c) FROM pagg_tab3 GROUP BY c collate "C" ORDER BY 1; SELECT c collate "C", count(c) FROM pagg_tab3 GROUP BY c collate "C" ORDER BY 1; +-- Partitionwise join should not be allowed too when the collation used by the +-- join keys doesn't match the partition key +SET enable_partitionwise_join TO false; +EXPLAIN (COSTS OFF) +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + +SET enable_partitionwise_join TO true; +EXPLAIN (COSTS OFF) +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; +SELECT t1.c, count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c GROUP BY 1 ORDER BY 1; + +-- OK when the join key uses the same collation. +EXPLAIN (COSTS OFF) +SELECT t1.c COLLATE "C", count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c COLLATE "C" GROUP BY t1.c COLLATE "C" ORDER BY 1; +SELECT t1.c COLLATE "C", count(t2.c) FROM pagg_tab3 t1 JOIN pagg_tab3 t2 ON t1.c = t2.c COLLATE "C" GROUP BY t1.c COLLATE "C" ORDER BY 1; + RESET enable_partitionwise_aggregate; RESET max_parallel_workers_per_gather; RESET enable_incremental_sort; -- 2.43.0