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authorTom Lane <tgl@sss.pgh.pa.us>2017-09-21 18:13:11 -0400
committerTom Lane <tgl@sss.pgh.pa.us>2017-09-21 18:13:11 -0400
commita2b1eb23496e9abd695036e3cbb1d39c05618692 (patch)
tree73509b127b2ce4fa67b193045f4c44d466c87eb4 /src/backend/commands/analyze.c
parent97514bf88bd96a4f213fbe6ae6911ba1dd033b8b (diff)
downloadpostgresql-a2b1eb23496e9abd695036e3cbb1d39c05618692.tar.gz
postgresql-a2b1eb23496e9abd695036e3cbb1d39c05618692.zip
Give a better error for duplicate entries in VACUUM/ANALYZE column list.
Previously, the code didn't think about this case and would just try to analyze such a column twice. That would fail at the point of inserting the second version of the pg_statistic row, with obscure error messsages like "duplicate key value violates unique constraint" or "tuple already updated by self", depending on context and PG version. We could allow the case by ignoring duplicate column specifications, but it seems better to reject it explicitly. The bogus error messages seem like arguably a bug, so back-patch to all supported versions. Nathan Bossart, per a report from Michael Paquier, and whacked around a bit by me. Discussion: https://postgr.es/m/E061A8E3-5E3D-494D-94F0-E8A9B312BBFC@amazon.com
Diffstat (limited to 'src/backend/commands/analyze.c')
-rw-r--r--src/backend/commands/analyze.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 2b638271b3d..28b679d0307 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -370,10 +370,14 @@ do_analyze_rel(Relation onerel, int options, VacuumParams *params,
/*
* Determine which columns to analyze
*
- * Note that system attributes are never analyzed.
+ * Note that system attributes are never analyzed, so we just reject them
+ * at the lookup stage. We also reject duplicate column mentions. (We
+ * could alternatively ignore duplicates, but analyzing a column twice
+ * won't work; we'd end up making a conflicting update in pg_statistic.)
*/
if (va_cols != NIL)
{
+ Bitmapset *unique_cols = NULL;
ListCell *le;
vacattrstats = (VacAttrStats **) palloc(list_length(va_cols) *
@@ -389,6 +393,13 @@ do_analyze_rel(Relation onerel, int options, VacuumParams *params,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
col, RelationGetRelationName(onerel))));
+ if (bms_is_member(i, unique_cols))
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_COLUMN),
+ errmsg("column \"%s\" of relation \"%s\" is specified twice",
+ col, RelationGetRelationName(onerel))));
+ unique_cols = bms_add_member(unique_cols, i);
+
vacattrstats[tcnt] = examine_attribute(onerel, i, NULL);
if (vacattrstats[tcnt] != NULL)
tcnt++;