Tom Lane wrote:
> Andreas Pflug <pgadmin@pse-consulting.de> writes:
>
>> So postmaster doesn't clean up pg_listener,
>
>
> It never has. If you're complaining about this patch
> http://archives.postgresql.org/pgsql-committers/2005-10/msg00073.php
> you ought to say so, rather than expecting us to guess it from an
> out-of-context quote from another mailing list.
Not complaining, just RFC.
But I wonder why postmaster doesn't truncate pg_listener at restart,
since PIDs can't be valid any more (truncating would reduce bloating
too). A redesign based on shmem or so wouldn't keep the data either.
>
> As near as I can tell, the technique Jan describes is an abuse of
> pg_listener, and I won't feel any great sympathy when it does break
> completely, which it will do before long when pg_listener goes away
> in the planned rewrite of LISTEN/NOTIFY.
Well slony uses LISTEN for its main purpose too. I'd guess there's
always a demand to find out which backend is listening, so a pg_listener (probably a view wrapping a function) will be
necessary.
AFAICS a backend that notices loss of client connection will usually
clean up its listener entries, so apparently slony doesn't need to take
care of this, at least for 8.1 (with the postmaster crash exception).
Regards,
Andreas
