Re: Proposal: Conflict log history table for Logical Replication

On Mon, Dec 22, 2025 at 3:55 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
>
>
> Few comments:
> 1) when a conflict_log_destination is specified as log:
> create subscription sub1 connection 'dbname=postgres host=localhost
> port=5432' publication pub1 with ( conflict_log_destination='log');
> postgres=# select subname, subconflictlogrelid,sublogdestination from
> pg_subscription where subname = 'sub4';
> subname | subconflictlogrelid | sublogdestination
> ---------+---------------------+-------------------
> sub4 | 0 | log
> (1 row)
>
> Currently it displays as 0, instead we can show as NULL in this case

I also thought about it while reviewing, but I feel 0 makes more sense
as it is 'relid'. This is how it is shown currently in other tables.
See 'reltoastrelid':

postgres=# select relname, reltoastrelid from pg_class where relname='tab1';
relname | reltoastrelid
---------+---------------
tab1 | 0
(1 row)

>
> 3) Can we include pg_ in the conflict table to indicate it is an
> internally created table:
> +/*
> + * Format the standardized internal conflict log table name for a subscription
> + *
> + * Use the OID to prevent collisions during rename operations.
> + */
> +void
> +GetConflictLogTableName(char *dest, Oid subid)
> +{
> + snprintf(dest, NAMEDATALEN, "conflict_log_table_%u", subid);
> +}
>

There is already a discussion about it in [1]

[1]: https://www.postgresql.org/message-id/CAA4eK1KE%3DtNHcN3Qp0FZVwDnt4rF2zwHy8NgAdG3oPqixdzOsA%40mail.gmail.com

thanks
Shveta