Re: PG 10 release notes

On 2017-04-25 22:13:00 -0400, Bruce Momjian wrote:
> On Tue, Apr 25, 2017 at 06:40:08PM -0700, Andres Freund wrote:
> > On 2017-04-25 21:19:41 -0400, Bruce Momjian wrote:
> > > On Tue, Apr 25, 2017 at 06:51:47AM +0200, Petr Jelinek wrote:
> > > > Or the ability of logical decoding to follow timeline switches.
> > >
> > > When you say "logical decoding", you don't mean contrib/test_decoding?
> >
> > No. test_decoding is just an example output plugin ("formatting" the
> > changes), but there's in-production users of logical decoding out
> > there. So features adding to logical decoding in general, are worth to
> > be mention in general.
>
> Yes, but I am still trying to find out what changed because we don't
> ship much that does "decoding" except contrib/test_decoding. Are you
> saying logical information is included in WAL?

We ship an extension API [1] [2] that allows to use decoding. And that
the internals of that API now knows how to deal with timeline changes.
You could e.g. compare it with the FDW API now providing the ability to
do aggregate pushdown or such.

> > >> I also wonder if ability to run SQL queries on walsender connected to a
> > >> database is worth mentioning (replication=database kind of connection).

Yes, but we're still discussing the feature's exact look nearby.

Greetings,

Andres Freund

[1] https://www.postgresql.org/docs/devel/static/logicaldecoding.html
[2] https://www.postgresql.org/docs/devel/static/logicaldecoding-output-plugin.html