Re: [RFC] CREATE QUEUE (log-only table) for londiste/pgQ ccompatibility

On Thu, Oct 18, 2012 at 2:33 PM, Josh Berkus <josh@agliodbs.com> wrote:
>> I should also add that this is an switchable sync/asynchronous
>> transactional queue, whereas LISTEN/NOTIFY is a synchronous
>> transactional queue.
>
> Thanks for explaining.

New here, I missed half the conversation, but since it's been brought
up and (to me wrongfully) dismissed, I'd like to propose:

NOTIFY [ALL|ONE] [REMOTE|LOCAL|CLUSTER|DOWNSTREAM] ASYNCHRONOUSLY
LISTEN [REMOTE|LOCAL|CLUSTER|UPSTREAM] too for good measure.

That ought to work out fine as SQL constructs go, implementation aside.

That's not enough for matviews, but it is IMO a good starting point.
All you need after that, are triggers for notifying automatically upon
insert, and some mechanism to attach triggers to a channel for the
receiving side.

Since channels are limited to short strings, maybe a different kind of
object (but with similar manipulation syntax) ought to be created. The
CREATE QUEUE command, in fact, could be creating such a channel. The
channel itself won't be WAL-only, just the messages going through it.
This (I think) would solve locking issues.