Re: Implement waiting for wal lsn replay: reloaded

On Thu, Jan 1, 2026 at 7:16 PM Álvaro Herrera <alvherre@kurilemu.de> wrote:
> In 0002 you have this kind of thing:
>
> >                               ereport(ERROR,
> >                                               errcode(ERRCODE_QUERY_CANCELED),
> > -                                             errmsg("timed out while waiting for target LSN %X/%08X to be
replayed;current replay LSN %X/%08X", 
> > +                                             errmsg("timed out while waiting for target LSN %X/%08X to be %s;
current%s LSN %X/%08X", 
> >                                                          LSN_FORMAT_ARGS(lsn),
> > -                                                        LSN_FORMAT_ARGS(GetXLogReplayRecPtr(NULL))));
> > +                                                        desc->verb,
> > +                                                        desc->noun,
> > +                                                        LSN_FORMAT_ARGS(currentLSN)));
> > +                     }
>
>
> I'm afraid this technique doesn't work, for translatability reasons.
> Your whole design of having a struct with ->verb and ->noun is not
> workable (which is a pity, but you can't really fight this.) You need to
> spell out the whole messages for each case, something like
>
> if (lsntype == replay)
>    ereport(ERROR,
>            errcode(ERRCODE_QUERY_CANCELED),
>            errmsg("timed out while waiting for target LSN %X/%08X to be replayed; current standby_replay LSN
%X/%08X",
> else if (lsntype == flush)
>     ereport( ... )
>
> and so on.  This means four separate messages for translation for each
> message your patch is adding, which is IMO the correct approach.

+1
Thank you for catching this, Alvaro.  Yes, I think we need to get rid
of WaitLSNTypeDesc.  It's nice idea, but we support too many languages
to have something like this.

------
Regards,
Alexander Korotkov
Supabase