Re: Choosing PostgreSQL as the database for our next project

Johnny Ljunggren wrote:
> 1. Replication - multimaster
> I'll try to explain the setup to the best of my ability:
> Three centers:
> Main center - database with a backup database
> Center 1 - database with a backup database
> Center 2 - database with a backup database (same as center 1)
>
> Application on the three centers will use the local database but the
> data should be replicated to the others as well. So when the link
> between the main center and center 1/2 goes down applications will work
> as usual and when the link is up the data will be replicated back and
> forth so they are equal. I assume that not all of the databases and
> tables will be replicated though...
> I know that Oracle can do this and they call it multimaster. I read in
> the FAQ that presumably pgcluster can do this, but instead of digging
> through tons of info I'll ask try my luck here.
> Will PostgreSQL be able to do what I want? Any third party (commercial
> or not) solutions?

If you are talking multiple data centers located relatively far away
from each other in order to assure uptime, I have bad news for you.
Nobody has an "out of the box" multi-master replication solution for
your situation -- not even Oracle. Synchronous multi-master solutions
pretty much demand LAN-level latency in order to assure performance.
Async multi-master can be done across high latency connections but async
multi-master requires rolling your own replication code to handle/avoid
data conflict issues.