Horton

Re: Binary support for pgoutput plugin

Andres Freund <andres@anarazel.de>

View thread View on postgr.es
From: Andres Freund <andres@anarazel.de>
To: Chapman Flack <chap@anastigmatix.net>
Cc: Dave Cramer <davecramer@gmail.com>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, David Fetter <david@fetter.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-06-08T01:18:41Z
Lists: pgsql-hackers 
Hi,

On 2019-06-07 21:16:12 -0400, Chapman Flack wrote:
> On 06/07/19 21:01, Andres Freund wrote:
> > On 2019-06-07 20:52:38 -0400, Chapman Flack wrote:
> > That'd be a *lot* of additional complexity, and pretty much prohibitive
> > from a performance POV. We'd have to not continue decoding on the server
> > side *all* the time to give the client a chance to inquire additional
> > information.
> 
> Does anything travel in the client->server direction during replication?
> I thought I saw CopyBoth mentioned. Is there a select()/poll() being done
> so those messages can be received?

Yes, acknowledgements of how far data has been received (and how far
processed), which is then used to release resources (WAL, xid horizon)
and allow synchronous replication to block until something has been
received.

- Andres

Commits

  1. Weaken type-OID-matching checks in array_recv and record_recv.

  2. Fix construction of updated-columns bitmap in logical replication.

  3. Allow logical replication to transfer data in binary format.

  4. Phase 2 pgindent run for v12.