Re: Fw: Fw: postgresql in cluster of servers

On Thu, 9 Jan 2003, enediel wrote:

> No, pginfo, suposse this example
>
> Web server or cluster web server, it's unimportant
> |
> Postgresql cluster server containing{
> ...
> Real server 1 running postgresql processes
> Real server 2 running postgresql processes
> ....
> }
> |
> File server machine that contains all pg_databases
>
> Notice that the real servers don't have in their hard disk any database,
> they could have a link to the hard disk in the File server machine.

Postgresql cannot currently work this way.

It uses shared memory on a single image OS to maintain the database
coherently. when you cluster Postgresql across multiple machines,
currently you have to have two seperate and independant instances which
are synchronized by an external process of some sort.

since I/O is usually the single limiting factor, your suggested system
would likely be no faster than a single box with decent memory and CPUs in
it.