Thanks - this could be the issue - our system has three processes - two
background processes and a user-facing process, that could be doing what you
describe, since they are processing the same data.

Thanks,

Aaron



-----Original Message-----
From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of Ann W. Harrison
Sent: Saturday, May 21, 2005 12:28 PM
To: firebird-support@yahoogroups.com
Subject: Re: [firebird-support] Re: Fbserver eating CPU...not taking
advantage of memory

Aaron Abend wrote:

>
> My question was intended to see if there were some known issues that would
> prevent FB from using more memory, which might therefore put more pressure
> on the CPU (I know this can happen with SQL Server and Oracle).
>

Not particularly, though Firebird does tend to use less memory than some
other databases. Typically, however, the very high CPU usage is related
to index garbage collection - indexes with lots of duplicates and lots
of back versions of records. You said your application was single user,
but some single user applications make multiple connections and a
background connection that starts a snapshot transaction and never
closes it can cause old index entries to build up.

>
>
> I have increased the DefaultDbCachePages to 5120 pages and we use 16k

pages

> -so it should be able to go up to 80M on this machine (which is running xp
> with 512M ram). But all it uses is 20M. why won't it use more? Is some

other

> parameter limiting memory use? Or is memory simply not the problem and it
> just needs a ton of CPU to process the queries?

The page cache is allocated as pages are read - there's no pre-loading.
The symptom of too little cache is heavy I/O load, not CPU.


Regards,


Ann



++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Visit http://firebird.sourceforge.net and click the Resources item
on the main (top) menu. Try Knowledgebase and FAQ links !

Also search the knowledgebases at http://www.ibphoenix.com

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Yahoo! Groups Links