Re: why vacuum

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(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461