Horton

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

Peter Geoghegan <pg@heroku.com>

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From: Peter Geoghegan <pg@heroku.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Pavan Deolasee <pavan.deolasee@gmail.com>, Claudio Freire <klaussfreire@gmail.com>, Greg Stark <stark@mit.edu>, Simon Riggs <simon@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Jim Nasby <Jim.Nasby@bluetreble.com>, PostgreSQL-Dev <pgsql-hackers@postgresql.org>
Date: 2016-09-13T18:56:49Z
Lists: pgsql-hackers 
On Tue, Sep 13, 2016 at 11:51 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> I think it's probably wrong to worry that an array-of-arrays is going
> to be meaningfully slower than a single array here.  It's basically
> costing you some small number of additional memory references per
> tuple, which I suspect isn't all that relevant for a bulk operation
> that does I/O, writes WAL, locks buffers, etc.

This analysis makes perfect sense to me.


-- 
Peter Geoghegan

Commits

  1. Prefetch blocks during lazy vacuum's truncation scan

  2. Explain unaccounted for space in pgstattuple.