From: Bob Smith <bsmith@h-e.com>
To: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Postgres locking
Date: Tue, 25 Feb 2003 16:55:57 -0800
Message-ID: <10995E4C-4925-11D7-8FCC-0003933DD370@h-e.com> (raw)
I'm trying to use select for update locks in Postgres. When I do this:
begin work;
select data from table where key = 1 for update;
in two psql's running simultaneously, about half the time the second
transaction blocks and waits for the first to end (which is what I want
it to do), the other half the time I get this:
ERROR: XactLockTableWait: LockAcquire failed
and the transaction is aborted. I can't find any pattern, if I do the
same statements in the same order several times, it will be block one
time and error the next apparently at random. I also tried using LOCK
TABLE and found the same basic problem, sometimes the second
transaction will block, other times it will abort with:
ERROR: LockRelation: LockAcquire failed
Do I have a configuration problem? Is this a bug in Postgres? I'm
still running 7.2.1, would upgrading to 7.3 fix this?
Thanks!
Bob Smith
Hammett & Edison, Inc.
bsmith@h-e.com
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To: pgsql-sql@postgresql.org
Cc: bsmith@h-e.com
Subject: Re: Postgres locking
In-Reply-To: <10995E4C-4925-11D7-8FCC-0003933DD370@h-e.com>
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