From: Antonin Houska <ah@cybertec.at>
To: Bruce Momjian <bruce@momjian.us>
cc: tgl@sss.pgh.pa.us, andres@anarazel.de,
    pgsql-hackers@lists.postgresql.org
Subject: Re: xl_heap_header alignment?
In-reply-to: <20200822004048.GO13363@momjian.us>
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 <1058724.1595356403@sss.pgh.pa.us> <22193.1595393913@antos>
 <20200822004048.GO13363@momjian.us>
Comments: In-reply-to Bruce Momjian <bruce@momjian.us>
   message dated "Fri, 21 Aug 2020 20:40:48 -0400."
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Date: Sat, 22 Aug 2020 20:48:54 +0200
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Bruce Momjian <bruce@momjian.us> wrote:

> On Wed, Jul 22, 2020 at 06:58:33AM +0200, Antonin Houska wrote:
> > Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > =

> > > I don't particularly want to remove the field, but we ought to
> > > change or remove the comment.
> > =

> > I'm not concerned about the existence of the field as well. The commen=
t just
> > made me worried that I might be missing some fundamental concept. Than=
ks for
> > your opinion.
> =

> I have developed the attached patch to address this.

Thanks. I wasn't sure if I'm expected to send the patch and then I forgot.

If the comment tells that t_hoff can be computed (i.e. it's no necessary t=
o
include it in the structure), I think the comment should tell why it's yet
included. Maybe something about "historical reasons"? Perhaps we can say t=
hat
the storage used to be free due to padding, and that it's no longer so, bu=
t
it's still "cheap", so it's not worth to teach the REDO functions to compu=
te
the value.

-- =

Antonin Houska
Web: https://www.cybertec-postgresql.com