Re: Minimal logical decoding on standbys

Amit Khandekar <amitdkhan.pg@gmail.com>

From: Amit Khandekar <amitdkhan.pg@gmail.com>
To: Andreas Joseph Krogh <andreas@visena.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-01-21T02:57:42Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

On Fri, 17 Jan 2020 at 13:20, Andreas Joseph Krogh <andreas@visena.com> wrote:
>
> På torsdag 16. januar 2020 kl. 05:42:24, skrev Amit Khandekar <amitdkhan.pg@gmail.com>:
>
> On Fri, 10 Jan 2020 at 17:50, Rahila Syed <rahila.syed@2ndquadrant.com> wrote:
> >
> > Hi Amit,
> >
> > Can you please rebase the patches as they don't apply on latest master?
>
> Thanks for notifying. Attached is the rebased version.
>
>
> Will this patch enable logical replication from a standby-server?

Sorry for the late reply.
This patch only supports logical decoding from standby. So it's just
an infrastructure for supporting logical replication from standby. We
don't support creating a publication from standby, but the publication
on master is replicated on standby, so we might be able to create
subscription nodes that connect to existing publications on standby,
but basically we haven't tested whether the publication/subscription
model works with a publication on a physical standby. This patch is
focussed on providing a way to continue logical replication *after*
the standby is promoted as master.


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