Stephen J. Friedl wrote:

>
> The default Firebird hash modulo is 101, and I have been looking
> without success for a reason not to max it out. The code limits the
> value to 2048, and the largest prime below that is 2039.
>
> The only consideration I can think of is memory use, but these
> machines are 100% dedicated to the Firebird database and have no
> regular users. Most have 4G of RAM, some even more. Some of these
> machines get *minimum* hash chain lengths of 400.
>
> What is the downside to a 2039-sized LockHashSlots parameter?
>

If you've got chains that long, I'd max out the the slots. I'd also
try throttling back a bit on the size of the individual caches, since
every page in cache is lock.

Regards,


Ann