Re: Inconsistent LSN format in pg_waldump output
Álvaro Herrera <alvherre@kurilemu.de>
From: Álvaro Herrera <alvherre@kurilemu.de>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Japin Li <japinli@hotmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-07-02T18:57:45Z
Lists: pgsql-hackers
On 2025-Jul-03, Masahiko Sawada wrote:
> On Wed, Jul 2, 2025 at 10:56 PM Japin Li <japinli@hotmail.com> wrote:
> Interesting. While this is a better format, could it break
> compatibility with existing tools that for example compares LSN
> strings?
I think a tool would have to be severely miswritten in order to become
broken from this change. Our own code to scan LSNs is to use
scanf('%X/%X') which should work just fine with and without the leading
zeroes. I honestly don't see anybody coding this in any different way
that could not cope with the leading zeroes :-)
> > > Agreed. I believe %X/%08X is better.
> >
> > Patch to standardize LSN formatting with zero-padding.
>
> Thank you for updating the patch. I think this patch doesn't need to
> update .po files as we do that at once when doing the translation
> update.
Agreed. In fact these updates are probably harmful (they certainly
bloat the patch quite a bit). These files come from a different
repository, which you're welcome to provide a patch for, after the code
change lands in Postgres.
https://git.postgresql.org/cgit/pgtranslation/messages.git/
--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"Porque Kim no hacía nada, pero, eso sí,
con extraordinario éxito" ("Kim", Kipling)
Commits
-
Fix a couple more places in docs for pg_lsn change
- aa39b4e35ac6 19 (unreleased) landed
-
Adapt pg_upgrade test to pg_lsn output format difference
- 3adcf9fbd8ba 19 (unreleased) landed
-
Standardize LSN formatting by zero padding
- 2633dae2e487 19 (unreleased) landed