Feedback-ID: id4a34324:Fastmail
Date: Fri, 17 Jan 2025 10:45:28 -0500
From: Andres Freund <andres@anarazel.de>
To: Michael Paquier <michael@paquier.xyz>
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Remove XLogRecGetFullXid() in xlogreader.c?
Message-ID: <llia6ygeogdunvw5ps6alozpoksyx7g4ra43dozzmr35kmrzb2@fhprqqwp4fos>
References: <Z4nkAQ-lP7fKInbP@paquier.xyz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Z4nkAQ-lP7fKInbP@paquier.xyz>
Archived-At: <https://www.postgresql.org/message-id/llia6ygeogdunvw5ps6alozpoksyx7g4ra43dozzmr35kmrzb2%40fhprqqwp4fos>
Precedence: bulk

Hi,

On 2025-01-17 14:00:49 +0900, Michael Paquier wrote:
> XLogRecGetFullXid() has been introduced in 67b9b3ca3283 back in 2019,
> but as far as I can see this has never been used in the code and this
> is used nowhere in the core code.
>
> I have looked at Debian's codesearch and also looked at traces of it
> on github without seeing it being used anywhere.  Knowing that this
> was originally intended for a hypothetical undo log patch back then,
> for which no work has been done for years, is there any point in
> keeping this function in core?
> 
> This issue has been raised on a separate thread, where Noah has sent a
> patch to consolidate a bit some epoch calculations for
> FullTransactionIds, around here:
> https://www.postgresql.org/message-id/Z4i6MbUlZxjK1rRh@paquier.xyz
> 
> Removing it would have the benefit to do a bit less refactoring for
> some of the work of the other thread, and this removes all traces of
> -DFRONTEND in xlogreader.h.  ;)

-0.5

I think it is sensible infrastructure and we'll eventually end up using
it. The cost of having it fairly low. If it were a legacy thing that we
shouldn't introduce new users for it'd be a different story, but it's the
opposite.

Greetings,

Andres