Date: Thu, 27 May 2021 10:00:16 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, Dilip Kumar <dilipbalaut@gmail.com>,
	pgsql-hackers <pgsql-hackers@postgresql.org>,
	Robert Haas <robertmhaas@gmail.com>
Subject: Re: Move pg_attribute.attcompression to earlier in struct for
 reduced size?
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On Wed, May 26, 2021 at 08:35:46PM -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > The efficiency bit is probably going to be swamped by the addition of
> > the compression handling, given the amount of additional work we're now
> > doing in in reform_and_rewrite_tuple().
>=20
> Only if the user has explicitly requested a change of compression, no?

Andres' point is that we'd still initialize and run through
values_free at the end of reform_and_rewrite_tuple() for each tuple
even if there no need to do so.  Well, we could control the
initialization and the free() checks at the end of the routine if we
know that there has been at least one detoasted value, at the expense
of making the code a bit less clear, of course.
--
Michael

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