Re: listen/notify argument (old topic revisited)

On Tue, 2002-07-02 at 17:12, Bruce Momjian wrote:
> Tom Lane wrote:
> > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > Of course, a shared memory system probably is going to either do it
> > > sequentailly or have its own index issues, so I don't see a huge
> > > advantage to going to shared memory, and I do see extra code and a queue
> > > limit.
> >
> > Disk I/O vs. no disk I/O isn't a huge advantage? Come now.
>
> My assumption is that it throws to disk as backing store, which seems
> better to me than dropping the notifies. Is disk i/o a real performance
> penalty for notify, and is performance a huge issue for notify anyway,
> assuming autovacuum?

For me, performance would be one of the only concerns. Currently I use
two methods of finding changes, one is NOTIFY which directs frontends to
reload various sections of data, the second is a table which holds a
QUEUE of actions to be completed (which must be tracked, logged and
completed).

If performance wasn't a concern, I'd simply use more RULES which insert
requests into my queue table.