pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Jeff Davis <pgsql@j-davis.com>
To: Andres Freund <andres@anarazel.de>
Cc: Justin Pryzby <pryzby@telsasoft.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: pgsql-hackers@lists.postgresql.org, Jeff Janes <jeff.janes@gmail.com>
Subject: Re: explain HashAggregate to report bucket and memory stats
Date: Fri, 13 Mar 2020 10:53:17 -0700
Message-ID: <eed4d5447629fcaa0360f4b5b66921df39b19b96.camel@j-davis.com> (raw)
In-Reply-To: <20200313172707.tiaf3tdsslam77ne@alap3.anarazel.de>
References: <20200203145301.53mozz7gcdaklnjc@alap3.anarazel.de>
	<20200216000220.GF31889@telsasoft.com>
	<20200216175307.GJ31889@telsasoft.com>
	<20200219201037.GA21433@telsasoft.com>
	<20200222215335.bu4kky7el4nccls5@development>
	<20200225033532.GX31889@telsasoft.com>
	<20200301154540.GL29456@telsasoft.com>
	<20200306175859.d56ohskarwldyrrw@alap3.anarazel.de>
	<20200306213310.GM684@telsasoft.com>
	<f95260dc8cd3b5a4de85d9f89b5bae19dfbc4c13.camel@j-davis.com>
	<20200313172707.tiaf3tdsslam77ne@alap3.anarazel.de>

On Fri, 2020-03-13 at 10:27 -0700, Andres Freund wrote:
> On 2020-03-13 10:15:46 -0700, Jeff Davis wrote:
> > Also, is there a reason you report two different memory values
> > (hashtable and tuples)? I don't object, but it seems like a little
> > too
> > much detail.
> 
> Seems useful to me - the hashtable is pre-allocated based on
> estimates,
> whereas the tuples are allocated "on demand". So seeing the
> difference
> will allow to investigate the more crucial issue...

Then do we also want to report separately on the by-ref transition
values? That could be useful if you are using ARRAY_AGG and the states
grow larger than you might expect.

Regards,
	Jeff Davis







view thread (24+ messages)  latest in thread

Message-ID: <eed4d5447629fcaa0360f4b5b66921df39b19b96.camel@j-davis.com>
Permalink:  ../eed4d5447629fcaa0360f4b5b66921df39b19b96.camel@j-davis.com/
Also on:    postgresql.org/message-id/eed4d5447629fcaa0360f4b5b66921df39b19b96.camel@j-davis.com

 · 

reply
Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-hackers@postgresql.org
  Cc: pgsql@j-davis.com, andres@anarazel.de, pryzby@telsasoft.com, tomas.vondra@2ndquadrant.com, jeff.janes@gmail.com
  Subject: Re: explain HashAggregate to report bucket and memory stats
  In-Reply-To: <eed4d5447629fcaa0360f4b5b66921df39b19b96.camel@j-davis.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox