Subject Re: [firebird-support] memory use
Author Alexandre Benson Smith
Hi manoel,

manoel_sa wrote:

>I've done a quick seach but did not find any clear info on how to use
>available memory more effectively. I am using FB 2 beta on a
>x86/suse-linux with 2GB of mem and in my tests increasing
>DefaultDbCachePages seemed to have no effect (65535, pagesize 4k) on the
>time of some large queries (in fact, the actual database is
>small ~40 MB so I imagined some change).
In FB 1.5 and earlier don't use more han 10000 page buffers, it tends to
slow the things down.

If you want to use more memory for cache, increase the pagesize of your
database to 16kb, with 16kb pages and 10k pages ni the buffers you will
have 160MB of memory for buffers.

If your database is just 40MB if you set up a cache of 40, 80 or 160
does not matter since all data are on cache.

FB uses memory for other things like sorting, and have a lot of RAM
(like you have) in most cases help a lot

I think you have something wrong with your query, such a small database
(40MB) shouldn't have a "too" slow query.

Could you show us your problem ?

>Other DBs recommend tweaking shmmax and shmall, but I also didn't see
>any reference to this anywhere.
Cant comment on this...

see you !

Alexandre Benson Smith
THOR Software e Comercial Ltda
Santo Andre - Sao Paulo - Brazil