public inbox for [email protected]  

help / color / mirror / Atom feed

From: Bertrand Drouvot <[email protected]>
To: Michael Paquier <[email protected]>
Cc: [email protected]
Subject: Re: Clear padding in PgStat_HashKey keys
Date: Mon, 4 Nov 2024 08:52:04 +0000
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>

Hi,

On Mon, Nov 04, 2024 at 04:25:00PM +0900, Michael Paquier wrote:
> On Sun, Nov 03, 2024 at 04:25:41AM +0000, Bertrand Drouvot wrote:
> > We are using sizeof(PgStat_HashKey) in pgstat_cmp_hash_key() and we compute the
> > hash hash key in pgstat_hash_hash_key() using the PgStat_HashKey struct size as
> > input: this lead to unexpected results if the keys contain random data in the 
> > padding bytes.
> 
> So you've seen that your patch was behaving weirdly once you have
> added padding because the hash key size has been extended, leading to
> relfilenode entries not being fetched when they should, right?

Yeah, but not only the relfilenode ones. All kinds were affected as random data
was in the padding bytes for all of them.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com

view thread (5+ 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: Clear padding in PgStat_HashKey keys
  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