public inbox for [email protected]  

help / color / mirror / Atom feed

From: Andres Freund <[email protected]>
To: Michael Paquier <[email protected]>
Cc: Peter Eisentraut <[email protected]>
Cc: Jakub Wartak <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Cc: Robert Haas <[email protected]>
Subject: Re: pg_stat_get_activity(): integer overflow due to (int) * (int) for MemoryContextAllocHuge()
Date: Wed, 27 Sep 2023 18:37:11 -0700
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <CAKZiRmw8QSNVw2qNK-dznsatQqz+9DkCquxP0GHbbv1jMkGHMA@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>

Hi,

On 2023-09-28 07:53:45 +0900, Michael Paquier wrote:
> On Wed, Sep 27, 2023 at 10:29:25AM -0700, Andres Freund wrote:
> > Frankly, it seems like a quite bad idea to have such a high limit for
> > pgstat_track_activity_query_size. The overhead such a high value has will
> > surprise people...
> 
> Still it could have some value for some users with large analytical
> queries where the syslogger is not going to be a bottleneck?  It seems
> too late to me to change that, but perhaps the docs could be improved
> to tell that using a too high value can have performance consequences,
> while mentioning the maximum value.

I don't think the issue is syslogger, the problem is that suddenly accessing
pg_stat_activity requires gigabytes of memory. That's insane.

Greetings,

Andres Freund

view thread (5+ messages)

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]
  Subject: Re: pg_stat_get_activity(): integer overflow due to (int) * (int) for MemoryContextAllocHuge()
  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