From a28fa2947d2a507089605c47bbfa9016d457208c Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 18 May 2026 13:18:35 +0900 Subject: [PATCH] Fix issues with handling of expressions in extended stats restore This commit addresses some defects with the handling of expressions in pg_restore_extended_stats() and pg_clear_extended_stats(): - Misleading WARNING for an incorrect number of expressions, where the number of required expressions was reported as the number of elements given in input rather than the actual number of expressions expected by the extstats object definition. - Incorrect matching of expression names, where a key name was considered as valid as long as it matched with the prefix of a legit key name. For example "correlatio" given in input would match with "correlation", and be considered valid. The consequence of this bug was a silent discard of the input data, where the operation would be considered a success. The value associated to the prefixed key was not inserted in the catalogs, just ignored. pg_dump would not generate such input data patterns, but a user doing manual stats injection could. - Missing heap_freetuple() in pg_clear_extended_stats(), for the case where the extstats object in input does not match with its parent relation. Author: Chao Li Discussion: https://postgr.es/m/A7C11B83-7534-4A09-9071-FBD09175CFC8@gmail.com --- src/backend/statistics/extended_stats_funcs.c | 6 ++-- src/test/regress/expected/stats_import.out | 32 +++++++++++++++++-- src/test/regress/sql/stats_import.sql | 19 ++++++++++- 3 files changed, 52 insertions(+), 5 deletions(-) diff --git a/src/backend/statistics/extended_stats_funcs.c b/src/backend/statistics/extended_stats_funcs.c index 70393d3a904..ab748068225 100644 --- a/src/backend/statistics/extended_stats_funcs.c +++ b/src/backend/statistics/extended_stats_funcs.c @@ -886,7 +886,8 @@ key_in_expr_argnames(JsonbValue *key) Assert(key->type == jbvString); for (int i = 0; i < NUM_ATTRIBUTE_STATS_ELEMS; i++) { - if (strncmp(extexprargname[i], key->val.string.val, key->val.string.len) == 0) + if (strlen(extexprargname[i]) == key->val.string.len && + strncmp(extexprargname[i], key->val.string.val, key->val.string.len) == 0) return true; } return false; @@ -1592,7 +1593,7 @@ import_expressions(Relation pgsd, int numexprs, ereport(WARNING, errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("could not parse \"%s\": incorrect number of elements (%d required)", - argname, num_root_elements)); + argname, numexprs)); goto exprs_error; } @@ -1816,6 +1817,7 @@ pg_clear_extended_stats(PG_FUNCTION_ARGS) */ if (stxform->stxrelid != relid) { + heap_freetuple(tup); table_close(pg_stext, RowExclusiveLock); ereport(WARNING, errcode(ERRCODE_INVALID_PARAMETER_VALUE), diff --git a/src/test/regress/expected/stats_import.out b/src/test/regress/expected/stats_import.out index f421e83e232..183e68d65c2 100644 --- a/src/test/regress/expected/stats_import.out +++ b/src/test/regress/expected/stats_import.out @@ -2455,7 +2455,7 @@ WARNING: could not parse "exprs": root-level array required f (1 row) --- wrong number of exprs +-- wrong number of exprs, too few SELECT pg_catalog.pg_restore_extended_stats( 'schemaname', 'stats_import', 'relname', 'test_clone', @@ -2463,7 +2463,21 @@ SELECT pg_catalog.pg_restore_extended_stats( 'statistics_name', 'test_stat_clone', 'inherited', false, 'exprs', '[ { "avg_width": "4" } ]'::jsonb); -WARNING: could not parse "exprs": incorrect number of elements (1 required) +WARNING: could not parse "exprs": incorrect number of elements (2 required) + pg_restore_extended_stats +--------------------------- + f +(1 row) + +-- wrong number of exprs, too many +SELECT pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test_clone', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'test_stat_clone', + 'inherited', false, + 'exprs', '[ { "avg_width": "4" }, { "avg_width": "4" }, { "avg_width": "4" } ]'::jsonb); +WARNING: could not parse "exprs": incorrect number of elements (2 required) pg_restore_extended_stats --------------------------- f @@ -3256,6 +3270,20 @@ most_common_elems | {-1,0,1,2,3} most_common_elem_freqs | {0.25,0.25,0.5,0.25,0.25,0.25,0.5,0.25} elem_count_histogram | {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1.5} +-- bad: exprs param which is a prefix of a valid key name +SELECT pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'test_stat_mcelem', + 'inherited', false, + 'exprs', '[{ "n": "-1" }]'::jsonb); +WARNING: could not import element in expression -1: invalid key name + pg_restore_extended_stats +--------------------------- + f +(1 row) + -- ok: tsvector exceptions, test just the collation exceptions CREATE STATISTICS stats_import.test_stat_tsvec ON (length(name)), (to_tsvector(name)) FROM stats_import.test; SELECT pg_catalog.pg_restore_extended_stats( diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql index c1bf55690a6..6064b7722da 100644 --- a/src/test/regress/sql/stats_import.sql +++ b/src/test/regress/sql/stats_import.sql @@ -1750,7 +1750,7 @@ SELECT pg_catalog.pg_restore_extended_stats( 'statistics_name', 'test_stat_clone', 'inherited', false, 'exprs', '{ "avg_width": "4", "null_frac": "0" }'::jsonb); --- wrong number of exprs +-- wrong number of exprs, too few SELECT pg_catalog.pg_restore_extended_stats( 'schemaname', 'stats_import', 'relname', 'test_clone', @@ -1758,6 +1758,14 @@ SELECT pg_catalog.pg_restore_extended_stats( 'statistics_name', 'test_stat_clone', 'inherited', false, 'exprs', '[ { "avg_width": "4" } ]'::jsonb); +-- wrong number of exprs, too many +SELECT pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test_clone', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'test_stat_clone', + 'inherited', false, + 'exprs', '[ { "avg_width": "4" }, { "avg_width": "4" }, { "avg_width": "4" } ]'::jsonb); -- incorrect type of value: should be a string or a NULL. SELECT pg_catalog.pg_restore_extended_stats( 'schemaname', 'stats_import', @@ -2244,6 +2252,15 @@ WHERE e.statistics_schemaname = 'stats_import' AND e.inherited = false \gx +-- bad: exprs param which is a prefix of a valid key name +SELECT pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'test_stat_mcelem', + 'inherited', false, + 'exprs', '[{ "n": "-1" }]'::jsonb); + -- ok: tsvector exceptions, test just the collation exceptions CREATE STATISTICS stats_import.test_stat_tsvec ON (length(name)), (to_tsvector(name)) FROM stats_import.test; SELECT pg_catalog.pg_restore_extended_stats(