Re: Choosing PostgreSQL as the database for our next project

Johnny Ljunggren wrote:
> Hmm, okay. We're now looking at another, simpler, way to do it. The same
> setup but the clients on Center 1/2 will connect directly to the Main
> center (2Mb leased line). The databases on Center 1/2 will then just be
> a replica of the Main databases.
> The biggest issue though is what happens when the lines go down:
> 1. connect to local database server
> 2. line comes up => changes to local database sent to main database
> 3. connect to main database server
>
>  From what I understand this will be possible but I may need to roll my
> own replication code to handle data conflict issues? Especially since
> center 1/2 may be down at the same time and then might change the same
> data.
> How do the tools for this compare against the ones from Oracle?
>

It sounds like now is you have a master -> multi-slave setup. If master
goes down, people use slave instead w/ master re-replicating after it
comes back up. This config should be much easier to configure out of the
box -- you shouldn't need to write any custom app code.

What I'm not sure about though is what would happen with 2 slaves if
main goes down AND the connection between center 1 & 2 is also
disconnected. Others with more experience with the various master/slave
replication solutions might want to chime in now on how it would work.