Re: pg_walfile_name_offset can return inconsistent values

Hi,

On 2023-11-13 12:14:57 -0500, Bruce Momjian wrote:
> +SELECT *
> +FROM (values ('0/16ffffff'), ('0/17000000'), ('0/17000001')) as t(lsn),
> +     LATERAL pg_walfile_name_offset(lsn::pg_lsn),
> +     LATERAL pg_walfile_name(lsn::pg_lsn);
> +    lsn     |        file_name         | file_offset |     pg_walfile_name      
> +------------+--------------------------+-------------+--------------------------
> + 0/16ffffff | 000000010000000000000016 |    16777215 | 000000010000000000000016
> + 0/17000000 | 000000010000000000000017 |           0 | 000000010000000000000017
> + 0/17000001 | 000000010000000000000017 |           1 | 000000010000000000000017
> +(3 rows)

These would break when testing with a different segment size. Today that's not
the case...

Greetings,

Andres Freund