Re: why vacuum - Mailing list pgsql-sql

From Jim C. Nasby
Subject Re: why vacuum
Date
Msg-id 20051027175215.GJ63747@pervasive.com
Whole thread Raw
In response to Re: why vacuum  (Richard Huxton <dev@archonet.com>)
List pgsql-sql
On Thu, Oct 27, 2005 at 02:21:15PM +0100, Richard Huxton wrote:
> So - if your statement contains something non-deterministic that isn't 
> catered for in Mysql's code then it will break.
> 
> At it's simplest - if I write a function my_random() and then do:
>   UPDATE foo SET a=1 WHERE b < my_random();
> IF my_random() returns different results on different machines, then the 
> replication will be broken. See the manual entry below:
>   http://dev.mysql.com/doc/refman/5.0/en/replication-features.html
> 
> That's not to say the system is worthless - it works fine for many 
> people. But it does have limitations.

And you can easily have multi-master syncronous replication in
PostgreSQL using the same idea; just see pgCluster.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461


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