Re: VACUUMs take twice as long across all nodes - Mailing list pgsql-performance

From Andrew Sullivan
Subject Re: VACUUMs take twice as long across all nodes
Date
Msg-id 20061029153404.GF14585@phlogiston.dyndns.org
Whole thread Raw
In response to Re: VACUUMs take twice as long across all nodes  (Gavin Hamill <gdh@laterooms.com>)
Responses Re: VACUUMs take twice as long across all nodes
List pgsql-performance
On Sun, Oct 29, 2006 at 03:08:26PM +0000, Gavin Hamill wrote:
>
> This is interesting, but I don't understand.. We've done a full restore
> from one of these pg_dump backups before now and it worked just great.
>
> Sure I had to DROP SCHEMA _replication CASCADE to clear out all the
> slony-specific triggers etc., but the new-master ran fine, as did
> firing up new replication to the other nodes :)
>
> Was I just lucky?

Yes.  Slony alters data in the system catalog for a number of
database objects on the replicas.  It does this in order to prevent,
for example, triggers from firing both on the origin and the replica.
(That is the one that usually bites people hardest, but IIRC it's not
the only such hack in there.)  This was a bit of a dirty hack that
was supposed to be cleaned up, but that hasn't been yet.  In general,
you can't rely on a pg_dump of a replica giving you a dump that, when
restored, actually works.

A

--
Andrew Sullivan  | ajs@crankycanuck.ca
Everything that happens in the world happens at some place.
        --Jane Jacobs

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