Horton

Re: (auto)vacuum truncate exclusive lock

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@2ndquadrant.com>
Cc: Kevin Grittner <kgrittn@ymail.com>, Jeff Janes <jeff.janes@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2013-04-12T17:21:28Z
Lists: pgsql-hackers 
Andres Freund <andres@2ndquadrant.com> writes:
> On 2013-04-12 13:09:02 -0400, Tom Lane wrote:
>> However, we're still thinking too small.  I've been wondering whether we
>> couldn't entirely remove the dirty, awful kluges that were installed in
>> the lock manager to kill autovacuum when somebody blocked behind it.
>> This mechanism should ensure that AV never takes an exclusive lock
>> for long enough to be a serious problem, so do we need that anymore?

> Wouldn't that make DROP TABLE stop working while autovac is processing
> the table?

Meh ... I guess you're right.  I wasn't thinking about exclusive locks
being taken elsewhere.

			regards, tom lane