Re: notification: pg_notify ? - Mailing list pgsql-hackers

From Mikhail Terekhov
Subject Re: notification: pg_notify ?
Date
Msg-id 3CAB19A5.3040103@emc.com
Whole thread Raw
In response to notification: pg_notify ?  (Neil Conway <nconway@klamath.dyndns.org>)
Responses Re: notification: pg_notify ?  (Gavin Sherry <swm@linuxworld.com.au>)
List pgsql-hackers

Tom Lane wrote:

> There is a very significant performance problem with LISTEN/NOTIFY
> via pg_listener: in any application that generates notifications at
> a significant rate, pg_listener will accumulate dead tuples at that
> same rate, and we will soon find ourselves wasting lots of time
> scanning through dead tuples.  Frequent VACUUMs might help, but the


That's unfortunate, may be if backend could reuse tuple on updates could help?


> whole thing is really quite silly: why are we using a storage mechanism
> that's designed entirely for *stable* storage of data to pass inherently
> *transient* signals?  If the system crashes, we have absolutely zero



Because there is no other easy way to guarantee message delivery?


> interest in the former contents of pg_listener (and indeed need to go
> to some trouble to get rid of them).


There is no free beer :)

Regards,
Mikhail Terekhov





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