Re: Vacuum: allow usage of more than 1GB of work mem

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Claudio Freire <klaussfreire@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-04-06T20:33:14Z
Lists: pgsql-hackers
Claudio Freire wrote:

> On Fri, Apr 6, 2018 at 11:00 AM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

> > FWIW I liked the idea of having this abstraction possibly do other
> > things -- for instance to vacuum brin indexes you'd like to mark index
> > tuples as "containing tuples that were removed" and eventually
> > re-summarize the range.  With the current interface we cannot do that,
> > because vacuum expects brin vacuuming to ask for each heap tuple "is
> > this tid dead?" and of course we don't have a list of tids to ask for.
> > So if we can ask instead "how many dead tuples does this block contain?"
> > brin vacuuming will be much happier.
> 
> I don't think either patch gives you that.
> 
> The bulkdelete interface is part of the indexam and unlikely to change
> in this patch.

I'm sure you're correct.  I was just saying that with the abstract
interface it is easier to implement what I suggest as a follow-on patch.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


Commits

  1. Prefetch blocks during lazy vacuum's truncation scan

  2. Explain unaccounted for space in pgstattuple.