public inbox for [email protected]  
help / color / mirror / Atom feed
From: Frédéric Yhuel <[email protected]>
To: Nathan Bossart <[email protected]>
Cc: Robert Haas <[email protected]>
Cc: Imseih (AWS), Sami <[email protected]>
Cc: David Rowley <[email protected]>
Cc: Joe Conway <[email protected]>
Cc: Michael Banck <[email protected]>
Cc: Laurenz Albe <[email protected]>
Cc: Melanie Plageman <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: New GUC autovacuum_max_threshold ?
Date: Mon, 12 Aug 2024 15:41:26 +0200
Message-ID: <[email protected]> (raw)
In-Reply-To: <ZrPprRLBzi1YUBLn@nathan>
References: <CA+Tgmoa9FzNLNtD-PYptJP1ApV=a57RwqOVypb0gL5uLzLtCFQ@mail.gmail.com>
	<CAApHDvo8DWyt4CWhF=NPeRstz_78SteEuuNDfYO7cjp=7YTK4g@mail.gmail.com>
	<CA+TgmoaCQ_GCwn3V8uXc+60oSJivY6ouiAqe81Z3h1kT6zMMYQ@mail.gmail.com>
	<20240507211702.GA2720371@nathanxps13>
	<[email protected]>
	<CA+TgmoYF3HqEUArbsqtCtP7YMJ62G3U8W1mSmZFZoCK8uBSi9g@mail.gmail.com>
	<[email protected]>
	<CA+TgmoaER+O40PA_CB8eSKm7KT37wDT+-y_mnsWXb9-Keivu1Q@mail.gmail.com>
	<ZnD509Q1jROYKhz_@nathan>
	<[email protected]>
	<ZrPprRLBzi1YUBLn@nathan>



On 8/7/24 23:39, Nathan Bossart wrote:
> I've attached a new patch to show roughly what I think this new GUC should
> look like.  I'm hoping this sparks more discussion, if nothing else.
>

Thank you. FWIW, I would prefer a sub-linear growth, so maybe something 
like this:

vacthresh = Min(vac_base_thresh + vac_scale_factor * reltuples, 
vac_base_thresh + vac_scale_factor * pow(reltuples, 0.7) * 100);

This would give :

* 386M (instead of 5.1 billion currently) for a 25.6 billion tuples table ;
* 77M for a 2.56 billion tuples table (Robert's example) ;
* 15M (instead of 51M currently) for a 256M tuples table ;
* 3M (instead of 5M currently) for a 25.6M tuples table.

The other advantage is that you don't need another GUC.

> On Tue, Jun 18, 2024 at 12:36:42PM +0200, Frédéric Yhuel wrote:
>> By the way, I wonder if there were any off-list discussions after Robert's
>> conference at PGConf.dev (and I'm waiting for the video of the conf).
> 
> I don't recall any discussions about this idea, but Robert did briefly
> mention it in his talk [0].
> 
> [0] https://www.youtube.com/watch?v=RfTD-Twpvac
> 

Very interesting, thanks!






view thread (16+ messages)  latest in thread

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: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: New GUC autovacuum_max_threshold ?
  In-Reply-To: <[email protected]>

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

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