Re: (auto)vacuum truncate exclusive lock

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kevin Grittner <kgrittn@ymail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2013-04-12T19:18:37Z
Lists: pgsql-hackers
Kevin Grittner <kgrittn@ymail.com> writes:
> For now what I'm suggesting is generating statistics in all the
> cases it did before, plus the case where it starts truncation but
> does not complete it. The fact that before this patch there were
> cases where the autovacuum worker was killed, resulting in not
> generating needed statistics seems like a bug, not a behavior we
> need to preserve.

Well, in the case where it gets killed, it's still not gonna generate
statistics.  What we've really got here is a new case that did not exist
before, namely that it voluntarily stops truncating.  But I agree that
modeling that case's behavior on the kill case was poorly thought out.

In other words, yes, I think we're on the same page.

			regards, tom lane