public inbox for [email protected]  
help / color / mirror / Atom feed
From: Alvaro Herrera <[email protected]>
To: Michael Paquier <[email protected]>
Cc: Rahila Syed <[email protected]>
Cc: PostgreSQL-development <[email protected]>
Subject: Re: Enhancing Memory Context Statistics Reporting
Date: Thu, 14 Nov 2024 12:48:47 +0100
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 2024-Nov-14, Michael Paquier wrote:

> Already mentioned previously at [1] and echoing with some surrounding
> arguments, but I'd suggest to keep it simple and just remove entirely
> the part of the patch where the stats information gets spilled into
> disk.  With more than 6000-ish context information available with a
> hard limit in place, there should be plenty enough to know what's
> going on anyway.

Functionally-wise I don't necessarily agree with _removing_ the spill
code, considering that production systems with thousands of tables would
easily reach that number of contexts (each index gets its own index info
context, each regexp gets its own memcxt); and I don't think silently
omitting a fraction of people's memory situation (or erroring out if the
case is hit) is going to make us any friends.

That said, it worries me that we choose a shared memory size so large
that it becomes impractical to hit the spill-to-disk code in regression
testing.  Maybe we can choose a much smaller limit size when
USE_ASSERT_CHECKING is enabled, and use a test that hits that number?
That way, we know the code is being hit and tested, without imposing a
huge memory consumption on test machines.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"Tiene valor aquel que admite que es un cobarde" (Fernandel)






view thread (8+ 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]
  Subject: Re: Enhancing Memory Context Statistics Reporting
  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