Обсуждение: Listen / Notify questions

Hi,

Two questions: 

1. Is there a way to determine which sessions are listening for a
certain notify message?
2. If a session ends without "unlisten" (e.g. my listening program
crashes), is that session automatically removed from the list of
sessions that should be notified?

-- 
Groeten,

Joost Kraaijeveld
Askesis B.V.
Molukkenstraat 14
6524NB Nijmegen
tel: 024-3888063 / 06-51855277
fax: 024-3608416
web: www.askesis.nl

On Sun, Jul 09, 2006 at 11:43:15AM +0200, Joost Kraaijeveld wrote:
> 1. Is there a way to determine which sessions are listening for a
> certain notify message?

SELECT * FROM pg_listener;

http://www.postgresql.org/docs/8.1/interactive/catalog-pg-listener.html

> 2. If a session ends without "unlisten" (e.g. my listening program
> crashes), is that session automatically removed from the list of
> sessions that should be notified?

According to the LISTEN documentation, "A session's listen registrations
are automatically cleared when the session ends."  You can confirm
this by querying pg_listener.

http://www.postgresql.org/docs/8.1/interactive/sql-listen.html

-- 
Michael Fuhr