Re: Listen / Notify - what to do when the queue is full

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Arnaud Betremieux <arnaud.betremieux@keyconsulting.fr>
Cc: Peter Eisentraut <peter_e@gmx.net>, Cyrille Chépélov <cyrille.chepelov@keyconsulting.fr>, pgsql-hackers@postgresql.org
Date: 2010-01-11T13:25:57Z
Lists: pgsql-hackers
Arnaud Betremieux <arnaud.betremieux@keyconsulting.fr> writes:
> 3) My use case          : NOTIFY channel 'pay'||'load' (actually NOTIFY 
> channel '<table_name>#'||OLD.id)
> 4) Taken one step further : NOTIFY channel (SELECT payload FROM payloads 
> WHERE ...)

> I'm working on a proof of concept patch to use Joachim's new notify 
> function to introduce case 3. I think this means going through the 
> planner and executor, so I might as well do case 4 as well.

It would be a lot less work to introduce a function like send_notify()
that could be invoked within a regular SELECT.  Pushing a utility
statement through the planner/executor code path will do enough violence
to the system design that such a patch would probably be rejected out of
hand.

			regards, tom lane