Re: Logical decoding on standby

Hi,

On 2017-03-21 09:05:26 +0800, Craig Ringer wrote:
> > 0002 should be doable as a whole this release, I have severe doubts that
> > 0003 as a whole has a chance for 10 - the code is in quite a raw shape,
> > there's a significant number of open ends. I'd suggest breaking of bits
> > that are independently useful, and work on getting those committed.
>
> That would be my preference too.

> The parts I think are important for Pg10 are:

> * Ability to create logical slots on replicas

Doesn't this also imply recovery conflicts on DROP DATABASE? Besides,
allowing to drop all slots using a database upon DROP DATABASE, is a
useful thing on its own.

But I have to admit, I've *severe* doubts about getting the whole
infrastructure for slot creation on replica into 10. The work is far
from ready, and we're mere days away from freeze.

> * Ability to advance (via feedback or via SQL function) - no need to
> actually decode and call output plugins at al

That pretty much requires decoding, otherwise you really don't know how
much WAL you have to retain.

> * Ability to drop logical slots on replicas

That shouldn't actually require any changes, no?

Greetings,

Andres Freund