Subject Re: [firebird-support] Re: Oldest Snapshot and Performance Issues
Author Helen Borrie
At 06:48 AM 26/10/2005 +0000, you wrote:

>When setting the value to 1,000 we did some research including
>checking "The Firebird Book". One suggestion on page 245 is to try a
>cache setting of two-thirds of available free memory which would have
>us using a buffer setting of about 3,000.

Oh, hmmm, that was talking about the Superserver buffers, which are shared
by all connections. It's a different boat.

And don't overlook the fact that your average use of RAM is in no way
indicative of your typical use of RAM for memory-intensive stuff like
sorting. If RAM isn't available for sorts, the engine will store the
intermediate streams in disk files. If you have plenty of RAM available
and frequent queries that ORDER BY or GROUP BY, you could investigate
bumping up the RAM allocation for sorting, provided you spend less on page
caches, of course. (You can configure this in firebird.conf; but don't
forget that each connection is a process with its own discrete RAM
requirements, so spend wisely.)

Still, I don't have anything to add and I've deadlines to meet.