> Using a cache setting of 1024 pages and a page size of 4KB, each
> database would need 4MB of cache. Accordingly, 500 databases would need
> only 2GB of RAM.
>
> This is not an exceptional amount of memory.

Sean,

It is exceptional for a single 32 bit fbserver process. I have no idea
about SPARC though (how many bit is that platform?).

I personally wouldn't use the SS engine to handle that sort of number
of databases. We had some problems when there were 30 databases so we
switched to classic on those servers (search archives around late feb
early mar 06), and it has been seemless since.

SS has additional problems if corruption occurs in a single database,
it will restart the service, abandoning the active work in 500
databases. With CS, only the connection to the database that
encountered the corruption is lost.

500 databases doesn't really tell you much though. I mean, depending
on the size of the database and the frequency and complexity of
operations, for some databases, running 4 on a single server would be
a bad idea, and others could be hundreds. Also, we do not know whether
500 will actually be accessed at a single time, or whether there is
500 potential databases, but chances are only 30 will be hit at any
point in time.

Personally I wouldn't lose too much sleep over the question, we
switched from superserver to classic with under 3 minutes of downtime
on each of our production servers.

Adam