Improve pg_clear_extended_stats() with incorrect relation/stats combination

Issue fat-fingered in d756fa1019ff, noticed while doing more review of
the main patch set proposed.  I have missed the fact that this can be
triggered by specifying an extended stats object that does not match
with the relation specified and already locked.  Like the cases where
an object defined in input is missing, the code is changed to issue a
WARNING instead of a confusing cache lookup failure.

A regression test is added to cover this case.

Discussion: https://postgr.es/m/CADkLM=dpz3KFnqP-dgJ-zvRvtjsa8UZv8wDAQdqho=qN3kX0Zg@mail.gmail.com

diff --git a/src/backend/statistics/extended_stats_funcs.c b/src/backend/statistics/extended_stats_funcs.c
index 22b9750ce198e5dfe22c5f5874e761c7a9c397f9..b4b1bf26463a9cc03bc2a4759460736ee83a805c 100644 (file)
--- a/src/backend/statistics/extended_stats_funcs.c
+++ b/src/backend/statistics/extended_stats_funcs.c
@@ -220,8 +220,15 @@ pg_clear_extended_stats(PG_FUNCTION_ARGS)
     * started.
     */
    if (stxform->stxrelid != relid)
-       elog(ERROR, "cache lookup failed for extended stats %u: found relation %u but expected %u",
-            stxform->oid, stxform->stxrelid, relid);
+   {
+       table_close(pg_stext, RowExclusiveLock);
+       ereport(WARNING,
+               errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+               errmsg("could not clear extended statistics object \"%s\".\"%s\": incorrect relation \"%s\".\"%s\" specified",
+                      get_namespace_name(nspoid), stxname,
+                      relnspname, relname));
+       PG_RETURN_VOID();
+   }
 
    delete_pg_statistic_ext_data(stxform->oid, inherited);
    heap_freetuple(tup);

diff --git a/src/test/regress/expected/stats_import.out b/src/test/regress/expected/stats_import.out
index 68ddd619edb1c87476d17e5333053d540000b750..d61ab92d17b187e8b6cf317947ecb7b3837a2cd8 100644 (file)
--- a/src/test/regress/expected/stats_import.out
+++ b/src/test/regress/expected/stats_import.out
@@ -1443,6 +1443,18 @@ WARNING:  could not find extended statistics object "stats_import"."ext_stats_no
  
 (1 row)
 
+-- Incorrect relation/extended stats combination
+SELECT pg_clear_extended_stats(schemaname => 'stats_import',
+  relname => 'test',
+  statistics_schemaname => 'stats_import',
+  statistics_name => 'test_stat_clone',
+  inherited => false);
+WARNING:  could not clear extended statistics object "stats_import"."test_stat_clone": incorrect relation "stats_import"."test" specified
+ pg_clear_extended_stats 
+-------------------------
+ 
+(1 row)
+
 -- Check that records are removed after a valid clear call.
 SELECT COUNT(*), e.inherited FROM pg_stats_ext AS e
   WHERE e.statistics_schemaname = 'stats_import' AND

diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql
index 04d15202e654f79c66f3203cb1d29078bf2188b5..d1934a8a42bf2f71e2ff0e757fb78addcd2df4f4 100644 (file)
--- a/src/test/regress/sql/stats_import.sql
+++ b/src/test/regress/sql/stats_import.sql
@@ -1044,6 +1044,12 @@ SELECT pg_clear_extended_stats(schemaname => 'stats_import',
   statistics_schemaname => 'stats_import',
   statistics_name => 'ext_stats_not_exist',
   inherited => false);
+-- Incorrect relation/extended stats combination
+SELECT pg_clear_extended_stats(schemaname => 'stats_import',
+  relname => 'test',
+  statistics_schemaname => 'stats_import',
+  statistics_name => 'test_stat_clone',
+  inherited => false);
 
 -- Check that records are removed after a valid clear call.
 SELECT COUNT(*), e.inherited FROM pg_stats_ext AS e