Re: logical decoding and replication of sequences, take 2

On Thu, Aug 17, 2023 at 7:13 PM Ashutosh Bapat
<ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
> >
> > The attached patch merges the earlier improvements, except for the part
> > that experimented with adding a "fake" transaction (which turned out to
> > have a number of difficult issues).
>
> 0004 looks good to me. But I need to review the impact of not setting
> replorigin_session_origin_timestamp.

I think it will be good to set replorigin_session_origin_timestamp = 0
explicitly so as not to pick up a garbage value. The timestamp is
written to the commit record. Beyond that I don't see any use of it.
It is further passed downstream if there is cascaded logical
replication setup. But I don't see it being used. So it should be fine
to leave it 0. I don't think we can use logically replicated sequences
in a mult-master environment where the timestamp may be used to
resolve conflict. Such a setup will require a distributed sequence
management which can not be achieved by logical replication alone.

In short, I didn't find any hazard in leaving the
replorigin_session_origin_timestamp as 0.

--
Best Wishes,
Ashutosh Bapat