----- "Jamie Tufnell" <[EMAIL PROTECTED]> escribió:
 
> pgpool-II with heartbeat for failover.  The pgpool-II configuration
> matrix (http://pgpool.projects.postgresql.org/) isn't terribly clear
> (there's no legend) but it leads me to believe failover and load
> balancing are mutually exclusive options.  Is that so?

No, they are not. I have a PostgreSQL cluster at work with connection pooling, 
replication and load balancing. It does failover and failback (online recovery) 
via PCP commands of pgpool-II and it's working fine. Only real restriction of 
pgpool-II is that you can't use CURRENT_TIMESTAMP, SERIALS and such things that 
could produce different results on each node because the replication happens by 
replicating SQL sentences.

My next step is to try Master/Slave with pgpool-II and Slony-I. In this setup, 
pgpool-II lets Slony-I do the replication and it does the rest of stuff. As far 
as I know, Slony-I does not have the above mentioned restrictions (not that we 
have them at work as we use an ORM, but I can understand that for many people 
they are huge restrictions).

> About our environment: PostgreSQL 8.3.  Over 90% reads.  Low data
> turnover on all tables involved in most of those reads.  High data
> turnover on a select few tables.  Overall database size is quite
> small
> (1GB).

As I said, I cannot talk about Slony-I yet, but your case is basically my case, 
just that my database is 30 GB in size. pgpool-II is working fine by me. Given 
that inserts happen only because of nightly batch processes, I wouldn't really 
mind locking the tables if I had to use serials and such, although I would not 
like it.

Hope this helps. If you have any more questions about pgpool-II, or if you feel 
confused by the features in the README (I was, too, at the beginning), please 
let me know.

--
Jaume Sabater
http://linuxsilo.net/

"Ubi sapientas ibi libertas"

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