From: Justin Pryzby <pryzby@telsasoft.com>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, Dilip Kumar <dilipbalaut@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>
Subject: Re: Move pg_attribute.attcompression to earlier in struct for reduced size?
Date: Mon, 17 May 2021 16:05:44 -0500
Message-ID: <20210517210544.GJ373@telsasoft.com> (raw)
In-Reply-To: <20210517204803.iyk5wwvwgtjcmc5w@alap3.anarazel.de>
References: <20210517204803.iyk5wwvwgtjcmc5w@alap3.anarazel.de>
On Mon, May 17, 2021 at 01:48:03PM -0700, Andres Freund wrote:
> pg_attribute is one of the biggest table in a new cluster, and often the
> biggest table in production clusters. Its size is also quite relevant in
> memory, due to all the TupleDescs we allocate.
>
> I just noticed that the new attcompression increased the size not just
> by 1 byte, but by 4, due to padding. While an increase from 112 to 116
> bytes isn't the end of the world, it does seem worth considering using
> existing unused bytes instead?
+1
FYI: attcompression was an OID until a few weeks before the feature was merged,
and there were several issues related to that:
aa25d1089 - fixed two issues
226e2be38
--
Justin
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: pryzby@telsasoft.com, andres@anarazel.de, dilipbalaut@gmail.com, robertmhaas@gmail.com
Subject: Re: Move pg_attribute.attcompression to earlier in struct for reduced size?
In-Reply-To: <20210517210544.GJ373@telsasoft.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