Re: Minimal logical decoding on standbys

On Thu, 30 May 2019 at 20:13, Andres Freund <andres@anarazel.de> wrote:
>
> Hi,
>
> On 2019-05-30 19:46:26 +0530, Amit Khandekar wrote:
> > @@ -1042,7 +1042,8 @@ ReplicationSlotReserveWal(void)
> >  if (!RecoveryInProgress() && SlotIsLogical(slot))
> >  {
> >     ....
> >  }
> >  else
> >  {
> > -   restart_lsn = GetRedoRecPtr();
> > +   restart_lsn = SlotIsLogical(slot) ?
> > +                        GetXLogReplayRecPtr(&ThisTimeLineID) : GetRedoRecPtr();
> >
> > But then when I do pg_create_logical_replication_slot(), it hangs in
> > DecodingContextFindStartpoint(), waiting to find new records
> > (XLogReadRecord).
>
> But just till the primary has logged the necessary WAL records? If you
> just do CHECKPOINT; or such on the primary, it should succeed quickly?

Yes, it waits until there is a commit record, or (just tried) until a
checkpoint command.

>
> Greetings,
>
> Andres Freund



-- 
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company