Re: multi-tenant vs. multi-cluster

On Mar 18, 2011, at 11:47 AM, Ivan Voras wrote:

> On 18/03/2011 19:17, Ben Chobot wrote:
>
>> if we're talking an extra 50MB of memory per cluster, that will start to add up.
>
> Consider this: each such cluster will have:
>
> a) its own database files on the drives (WAL, data - increasing IO)

Oh, I hadn't thought about WAL. Good point.
But data files are a function of tables and indexes, right? Having them in different schemas or different clusters isn't going to change that. I guess there are system tables but those are relatively trivial - I think?

> b) its own postgresql processes (many of them) running in memory

I believe this is entirely a function of client connections.

> c) its own shared_buffers in memory.

Given that each application will be independent, I don't see a different between clusters and schemas here either.