From e3231bfb71b9796570c3858a9b0a8e593435d345 Mon Sep 17 00:00:00 2001 From: Corey Huinker Date: Tue, 10 Nov 2026 20:32:11 -0500 Subject: [PATCH v2 3/3] Allow empty arrays as input for pg_restore_extended_stats. Fix the case where a pg_restore_extended_stats call with parameters derived from existing statistics derived via pg_dump cannot be re-imported back into the table. It is possible for the statistics for range_length_histogram in an extended statistics expression to be an empty array. Empty arrays are considered to have 0 dimensions, which runs afoul of existing checks that expect exactly one dimension, thus preventing the otherwise legitimate statistics from being imported. This fix relaxes the case to allow 0 or 1 dimensional arrays to be constructed, and further adds checks for emptiness when trying to determine the number of items in an array. Reported-by: chunling qin <303677365@qq.com> Author: Corey Huinker Discussion: https://postgr.es/m/19842-ca042326dd2430a4@postgresql.org Bug: #19842 Backpatch-through: 19 --- src/backend/statistics/extended_stats_funcs.c | 8 +-- src/test/regress/expected/stats_import.out | 55 ++++++++++++++++++- src/test/regress/sql/stats_import.sql | 43 +++++++++++++++ 3 files changed, 101 insertions(+), 5 deletions(-) diff --git a/src/backend/statistics/extended_stats_funcs.c b/src/backend/statistics/extended_stats_funcs.c index 020d64086ce..219ce1963f0 100644 --- a/src/backend/statistics/extended_stats_funcs.c +++ b/src/backend/statistics/extended_stats_funcs.c @@ -1096,11 +1096,11 @@ array_in_safe(FmgrInfo *array_in, const char *s, Oid typid, int32 typmod, return (Datum) 0; } - if (ARR_NDIM(DatumGetArrayTypeP(result)) != 1) + if (ARR_NDIM(DatumGetArrayTypeP(result)) > 1) { ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), - errmsg("could not import element \"%s\" in expression %d: must be a one-dimensional array", + errmsg("could not import element \"%s\" in expression %d: must be a one-dimensional array or empty", element_name, exprnum))); return (Datum) 0; } @@ -1369,8 +1369,8 @@ import_pg_statistic(Relation pgsd, JsonbContainer *cont, { ArrayType *vals_arr = DatumGetArrayTypeP(stavalues); ArrayType *nums_arr = DatumGetArrayTypeP(stanumbers); - int nvals = ARR_DIMS(vals_arr)[0]; - int nnums = ARR_DIMS(nums_arr)[0]; + int nvals = (ARR_NDIM(vals_arr) > 0) ? ARR_DIMS(vals_arr)[0] : 0; + int nnums = (ARR_NDIM(nums_arr) > 0) ? ARR_DIMS(nums_arr)[0] : 0; if (nvals != nnums) { diff --git a/src/test/regress/expected/stats_import.out b/src/test/regress/expected/stats_import.out index 466582d364b..f15ef2e864b 100644 --- a/src/test/regress/expected/stats_import.out +++ b/src/test/regress/expected/stats_import.out @@ -3246,7 +3246,7 @@ SELECT pg_catalog.pg_restore_extended_stats( { "most_common_vals": "{{1,2},{3,4}}", "most_common_freqs": "{0.3,0.25,0.05,0.04}" }, { "most_common_vals": "{2}", "most_common_freqs": "{0.5}" } ]'::jsonb); -WARNING: could not import element "most_common_vals" in expression -1: must be a one-dimensional array +WARNING: could not import element "most_common_vals" in expression -1: must be a one-dimensional array or empty pg_restore_extended_stats --------------------------- f @@ -4357,6 +4357,59 @@ AND attname = 'id'; {} | {} (1 row) +-- BUG #19842 +TRUNCATE TABLE stats_import.test; +INSERT INTO stats_import.test(id, arange) +VALUES (1, int4range(1,5)), (2, 'empty'::int4range); +CREATE STATISTICS stats_import.range_stat ON (arange * int4range(1,10)) +FROM stats_import.test; +ANALYZE stats_import.test; +SELECT * FROM pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'range_stat', + 'inherited', 'f'::boolean, + 'exprs', '[{"avg_width": "13","null_frac": "0","n_distinct": "-1", + "range_empty_frac": "0.5"}]'::jsonb +); +WARNING: could not parse "exprs": invalid element in expression -1 +HINT: "range_length_histogram" and "range_empty_frac" must be both either strings or nulls. + pg_restore_extended_stats +--------------------------- + f +(1 row) + +SELECT * FROM pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'range_stat', + 'inherited', 'f'::boolean, + 'exprs', '[{"avg_width": "13","null_frac": "0","n_distinct": "-1", + "range_length_histogram": "{}", "range_empty_frac": "0.5"}]'::jsonb +); + pg_restore_extended_stats +--------------------------- + t +(1 row) + +SELECT * FROM pg_catalog.pg_restore_attribute_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'attname', 'arange', + 'inherited', 'f'::boolean, + 'null_frac', '0'::real, + 'avg_width', '10'::integer, + 'n_distinct', '-1'::real, + 'range_length_histogram', '{}'::text, + 'range_empty_frac', '0.5'::real +); + pg_restore_attribute_stats +---------------------------- + t +(1 row) + DROP SCHEMA stats_import CASCADE; NOTICE: drop cascades to 39 other objects DETAIL: drop cascades to view stats_import.pg_stats_stable diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql index 5d71acf106b..a64cf421240 100644 --- a/src/test/regress/sql/stats_import.sql +++ b/src/test/regress/sql/stats_import.sql @@ -3086,4 +3086,47 @@ WHERE schemaname = 'stats_import' AND tablename = 'test' AND attname = 'id'; +-- BUG #19842 +TRUNCATE TABLE stats_import.test; + +INSERT INTO stats_import.test(id, arange) +VALUES (1, int4range(1,5)), (2, 'empty'::int4range); + +CREATE STATISTICS stats_import.range_stat ON (arange * int4range(1,10)) +FROM stats_import.test; + +ANALYZE stats_import.test; + +SELECT * FROM pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'range_stat', + 'inherited', 'f'::boolean, + 'exprs', '[{"avg_width": "13","null_frac": "0","n_distinct": "-1", + "range_empty_frac": "0.5"}]'::jsonb +); + +SELECT * FROM pg_catalog.pg_restore_extended_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'statistics_schemaname', 'stats_import', + 'statistics_name', 'range_stat', + 'inherited', 'f'::boolean, + 'exprs', '[{"avg_width": "13","null_frac": "0","n_distinct": "-1", + "range_length_histogram": "{}", "range_empty_frac": "0.5"}]'::jsonb +); + +SELECT * FROM pg_catalog.pg_restore_attribute_stats( + 'schemaname', 'stats_import', + 'relname', 'test', + 'attname', 'arange', + 'inherited', 'f'::boolean, + 'null_frac', '0'::real, + 'avg_width', '10'::integer, + 'n_distinct', '-1'::real, + 'range_length_histogram', '{}'::text, + 'range_empty_frac', '0.5'::real +); + DROP SCHEMA stats_import CASCADE; -- 2.56.0