Until PostgreSQL 9.1, it was possible to run ALTER TABLE ... SET
STATISTICS without allow_system_table_mods. In PostgreSQL 9.2 and
later, this no longer works. This change was apparently accidental. (I
gave up after a while trying to bisect it exactly, but probably
something related to 1489e2f26a4c0318938b3085f50976512f321d84.)
(It didn't work on mapped relations, so it wasn't all roses.)
A comment in ATPrepSetStatistics() still makes references to this being
possible. I propose to remove this comment.
There was some discussion about (re-)allowing this and some other
commands like this, but after the recent changes to make
allow_system_table_mods easier to use, I think this has less urgency, so
I'd rather get the comment correct in the meantime.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From 203571a0402face9feb92a058d8423317501545e Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Wed, 4 Dec 2019 23:46:00 +0100
Subject: [PATCH] Remove comment about SET STATISTICS on system tables
It was once possible to do ALTER TABLE ... SET STATISTICS on system
tables without allow_sytem_table_mods. This was changed apparently by
accident between PostgreSQL 9.1 and 9.2, but a code comment still
claimed this was possible. Remove that comment. (Maybe someone wants
to revive that functionality, but not right now.)
---
src/backend/commands/tablecmds.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 5440eb9015..55b9b63336 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6707,10 +6707,8 @@ static void
ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum, Node
*newValue, LOCKMODE lockmode)
{
/*
- * We do our own permission checking because (a) we want to allow SET
- * STATISTICS on indexes (for expressional index columns), and (b) we
want
- * to allow SET STATISTICS on system catalogs without requiring
- * allowSystemTableMods to be turned on.
+ * We do our own permission checking because we want to allow SET
+ * STATISTICS on indexes (for expressional index columns).
*/
if (rel->rd_rel->relkind != RELKIND_RELATION &&
rel->rd_rel->relkind != RELKIND_MATVIEW &&
--
2.24.0
