Re: logical copy_replication_slot issues

On Mon, 9 Mar 2020 at 21:46, Arseny Sher <a(dot)sher(at)postgrespro(dot)ru> wrote:
>
>
> Masahiko Sawada <masahiko(dot)sawada(at)2ndquadrant(dot)com> writes:
>
> > /*
> > - * Create logical decoding context, to build the initial snapshot.
> > + * Create logical decoding context to find start point or, if we don't
> > + * need it, to 1) bump slot's restart_lsn and xmin 2) check plugin sanity.
> > */
> >
> > Do we need to numbering that despite not referring them?
>
> No, it just seemed clearer to me this way. I don't mind removing the
> numbers if you feel this is better.
>

Okay.

> > ctx = CreateInitDecodingContext(plugin, NIL,
> > - false, /* do not build snapshot */
> > + false, /* do not build data snapshot */
> > restart_lsn,
> > logical_read_local_xlog_page, NULL, NULL,
> > NULL);
> > I'm not sure this change makes the comment better. Could you elaborate
> > on the motivation of this change?
>
> Well, DecodingContextFindStartpoint always builds a snapshot allowing
> historical *catalog* lookups. This bool controls whether the snapshot
> should additionally be suitable for looking at the actual data, this is
> e.g. used by initial data sync in the native logical replication.

Okay.

Anyway, since the patch looks good to me I've marked this patch as
"Ready for Committer". I think we can defer these things to
committers.

Regards,

--
Masahiko Sawada http://www.2ndQuadrant.com/
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