Subject RE: [ib-support] How to utilize maximum memory.
Author Leyne, Sean

> How to configure Firebird or Interbase for using more than
> 65535 buffers per database. Each buffer is a 4Kb, isn't it?
> So server can utilize only 256Mb RAM, inspite of 2Gb
> avaliable. Gfix does not accept more than 65535 buffers.

The database cache size is actually dependent on the number of cached
pages and the database page size, thus given a max. page size of 16KB,
using a cache size of 65,535 pages -- 1GB of RAM would be used. But

Unless you are running IB v6.5, setting the cache page count to 65,535
is a *very* bad idea. There are known performance issues with a setting
above 10,000 pages. Thus, the effective maximum memory used by Firebird
is some 160Mb.

You will be happy to hear that in the next Firebird release (call it
v1.5), Dmitry Yemanov has added logic to allow for the remaining RAM to
be used by FB for temporary/sort files/datasets. Currently, the engine
pages these files to disk in increment of 128Kb. Thus, you will see a
dramatic increase in performance for medium to large sorts.