From aef713df81c613a56855a8d46aac198090ab1a5d Mon Sep 17 00:00:00 2001 From: jian he Date: Tue, 13 Jan 2026 10:15:13 +0800 Subject: [PATCH v1 1/1] proper handling examine_variable RelabelType discussion: https://postgr.es/m/ --- src/backend/utils/adt/selfuncs.c | 62 +++++++++++++++++-- .../regress/expected/collate.icu.utf8.out | 49 +++++++++++++++ src/test/regress/sql/collate.icu.utf8.sql | 32 ++++++++++ 3 files changed, 138 insertions(+), 5 deletions(-) diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 29fec655593..d6a26c48384 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -5661,8 +5661,34 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid, * RelabelType nodes here, because the prior stripping of PlaceHolderVars * may have brought separate RelabelTypes into adjacency. */ - while (IsA(basenode, RelabelType)) - basenode = (Node *) ((RelabelType *) basenode)->arg; + if (IsA(basenode, RelabelType)) + { + RelabelType *relabel = castNode(RelabelType, basenode); + Expr *expr = (Expr *) relabel; + + while (expr && IsA(expr, RelabelType)) + expr = ((RelabelType *) expr)->arg; + + if (exprCollation((Node *) expr) == relabel->resultcollid) + basenode = (Node *) expr; + else + { + /* + * A RelabelType is required when the input expression’s + * collation differs from the resulting resultcollid. + */ + RelabelType *newrelabel = makeNode(RelabelType); + + newrelabel->arg = (Expr *) expr; + newrelabel->resulttype = relabel->resulttype; + newrelabel->resulttypmod = relabel->resulttypmod; + newrelabel->resultcollid = relabel->resultcollid; + newrelabel->relabelformat = relabel->relabelformat; + newrelabel->location = relabel->location; + + basenode = (Node *) newrelabel; + } + } /* Fast path for a simple Var */ if (IsA(basenode, Var) && @@ -5909,9 +5935,35 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid, Assert(expr); - /* strip RelabelType before comparing it */ - if (expr && IsA(expr, RelabelType)) - expr = (Node *) ((RelabelType *) expr)->arg; + if (IsA(expr, RelabelType)) + { + RelabelType *relabel = castNode(RelabelType, expr); + Expr *rexpr = (Expr *) relabel; + + while (rexpr && IsA(rexpr, RelabelType)) + rexpr = ((RelabelType *) rexpr)->arg; + + if (exprCollation((Node *) rexpr) == relabel->resultcollid) + expr = (Node *) rexpr; + else + { + /* + * A RelabelType is required when the input + * expression’s collation differs from the resulting + * resultcollid. + */ + RelabelType *newrelabel = makeNode(RelabelType); + + newrelabel->arg = (Expr *) rexpr; + newrelabel->resulttype = relabel->resulttype; + newrelabel->resulttypmod = relabel->resulttypmod; + newrelabel->resultcollid = relabel->resultcollid; + newrelabel->relabelformat = relabel->relabelformat; + newrelabel->location = relabel->location; + + expr = (Node *) newrelabel; + } + } /* found a match, see if we can extract pg_statistic row */ if (equal(node, expr)) diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out index 1325e123877..263e7ce8ae4 100644 --- a/src/test/regress/expected/collate.icu.utf8.out +++ b/src/test/regress/expected/collate.icu.utf8.out @@ -11,6 +11,25 @@ SELECT getdatabaseencoding() <> 'UTF8' OR SET client_encoding TO UTF8; CREATE SCHEMA collate_tests; SET search_path = collate_tests; +create function check_estimated_rows(text) returns table (estimated int, actual int) +language plpgsql as +$$ +declare + ln text; + tmp text[]; + first_row bool := true; +begin + for ln in + execute format('explain analyze %s', $1) + loop + if first_row then + first_row := false; + tmp := regexp_match(ln, 'rows=(\d*) .* rows=(\d*)'); + return query select tmp[1]::int, tmp[2]::int; + end if; + end loop; +end; +$$; CREATE TABLE collate_test1 ( a int, b text COLLATE "en-x-icu" NOT NULL @@ -1461,6 +1480,36 @@ CREATE COLLATION case_sensitive (provider = icu, locale = ''); NOTICE: using standard form "und" for ICU locale "" CREATE COLLATION case_insensitive (provider = icu, locale = '@colStrength=secondary', deterministic = false); NOTICE: using standard form "und-u-ks-level2" for ICU locale "@colStrength=secondary" +CREATE TABLE test_stats_ext_coll (a text, b text, c int); +INSERT INTO test_stats_ext_coll SELECT chr(65 + g % 52) FROM generate_series(1, 500) g; +CREATE STATISTICS test_stats_ext_coll_stx ON (a COLLATE case_insensitive) FROM test_stats_ext_coll; +ANALYZE test_stats_ext_coll; +SELECT * FROM check_estimated_rows ($$ SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE "C" $$); + estimated | actual +-----------+-------- + 52 | 52 +(1 row) + +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE "POSIX" $$); + estimated | actual +-----------+-------- + 52 | 52 +(1 row) + +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE case_insensitive $$); + estimated | actual +-----------+-------- + 32 | 32 +(1 row) + +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a $$); + estimated | actual +-----------+-------- + 52 | 52 +(1 row) + +DROP FUNCTION check_estimated_rows; +DROP TABLE test_stats_ext_coll; SELECT 'abc' <= 'ABC' COLLATE case_sensitive, 'abc' >= 'ABC' COLLATE case_sensitive; ?column? | ?column? ----------+---------- diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql index b6c54503d21..b5c22bebfa6 100644 --- a/src/test/regress/sql/collate.icu.utf8.sql +++ b/src/test/regress/sql/collate.icu.utf8.sql @@ -16,6 +16,26 @@ CREATE SCHEMA collate_tests; SET search_path = collate_tests; +create function check_estimated_rows(text) returns table (estimated int, actual int) +language plpgsql as +$$ +declare + ln text; + tmp text[]; + first_row bool := true; +begin + for ln in + execute format('explain analyze %s', $1) + loop + if first_row then + first_row := false; + tmp := regexp_match(ln, 'rows=(\d*) .* rows=(\d*)'); + return query select tmp[1]::int, tmp[2]::int; + end if; + end loop; +end; +$$; + CREATE TABLE collate_test1 ( a int, b text COLLATE "en-x-icu" NOT NULL @@ -561,6 +581,18 @@ SELECT * FROM test6a WHERE b = ARRAY['äbc'] COLLATE ctest_nondet; CREATE COLLATION case_sensitive (provider = icu, locale = ''); CREATE COLLATION case_insensitive (provider = icu, locale = '@colStrength=secondary', deterministic = false); +CREATE TABLE test_stats_ext_coll (a text, b text, c int); +INSERT INTO test_stats_ext_coll SELECT chr(65 + g % 52) FROM generate_series(1, 500) g; +CREATE STATISTICS test_stats_ext_coll_stx ON (a COLLATE case_insensitive) FROM test_stats_ext_coll; +ANALYZE test_stats_ext_coll; + +SELECT * FROM check_estimated_rows ($$ SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE "C" $$); +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE "POSIX" $$); +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a COLLATE case_insensitive $$); +SELECT * FROM check_estimated_rows ($$SELECT count(*) FROM test_stats_ext_coll GROUP BY a $$); +DROP FUNCTION check_estimated_rows; +DROP TABLE test_stats_ext_coll; + SELECT 'abc' <= 'ABC' COLLATE case_sensitive, 'abc' >= 'ABC' COLLATE case_sensitive; SELECT 'abc' <= 'ABC' COLLATE case_insensitive, 'abc' >= 'ABC' COLLATE case_insensitive; -- 2.34.1