From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tender Wang <tndrwang@gmail.com>
Cc: jian he <jian.universality@gmail.com>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: not null constraints, again
Date: Fri, 20 Sep 2024 09:31:13 +0200
Message-ID: <202409200731.rxqstsmup5nl@alvherre.pgsql> (raw)
In-Reply-To: <CAHewXNm+qmT6V0HJCsjsO9R7EyJwXyz8mbBOY3ES7cR7K3djvA@mail.gmail.com>
On 2024-Sep-20, Tender Wang wrote:
> jian he <jian.universality@gmail.com> 于2024年9月20日周五 11:34写道：
>
> > another bug.
> > I will dig later, just want to share it first.
> >
> > minimum producer:
> > drop table if exists pp1,cc1, cc2,cc3;
> > create table pp1 (f1 int );
> > create table cc1 () inherits (pp1);
> > create table cc2() inherits(pp1,cc1);
> > create table cc3() inherits(pp1,cc1,cc2);
> >
> > alter table pp1 alter f1 set not null;
> > ERROR: tuple already updated by self
>
> I guess some place needs call CommandCounterIncrement().
Yeah ... this fixes it:
inline patch 1: src/backend/commands/tablecmds.c (+2/-6 lines) download inline-1.patchdiff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.cindex 579b8075b5..3f66e43b9a 100644--- a/src/backend/commands/tablecmds.c+++ b/src/backend/commands/tablecmds.c@@ -7877,12 +7877,6 @@ ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName,
{
List *children;
- /*- * Make previous addition visible, in case we process the same- * relation again while chasing down multiple inheritance trees.- */- CommandCounterIncrement();-
children = find_inheritance_children(RelationGetRelid(rel),
lockmode);
@@ -7890,6 +7884,8 @@ ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName,
{
Relation childrel = table_open(childoid, NoLock);
+ CommandCounterIncrement();+
ATExecSetNotNull(wqueue, childrel, conName, colName,
recurse, true, lockmode);
table_close(childrel, NoLock);
I was trying to save on the number of CCIs that we perform, but it's
likely not a wise expenditure of time given that this isn't a very
common scenario anyway. (Nobody with thousands of millions of children
tables will try to run thousands of commands in a single transaction
anyway ... so saving a few increments doesn't make any actual
difference. If such people exist, they can show us their use case and
we can investigate and fix it then.)
--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/
"This is what I like so much about PostgreSQL. Most of the surprises
are of the "oh wow! That's cool" Not the "oh shit!" kind. :)"
Scott Marlowe, http://archives.postgresql.org/pgsql-admin/2008-10/msg00152.php
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: alvherre@alvh.no-ip.org, tndrwang@gmail.com, jian.universality@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: not null constraints, again
In-Reply-To: <202409200731.rxqstsmup5nl@alvherre.pgsql>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox