Re: buffer pool

On 1 Aug 2002 07:19:50 -0700, daud11_at_hotmail.com (Daud) wrote:

>I was reading the Oracle 8i doc on Designing and Tuning for
>Performance when I came across a section on how to set the value of
>db_block_lru_latches and db_writer_processes. My question is how do I
>know if I have multiple buffer pool (default, keep and recycle)? I
>never explicitly set it to anything in my table creation script. I
>guess I only have one (default). Am I correct? Is there a way to
>confirm this?
>

check out the init.ora or v$sgastat or v$buffer_pool, though I'm not 100 percent sure the latter thingy already exists in 8i. By default the keep and recycle pools are NOT configured.

>My oracle is running on a 8-cpu unix machine. By default,
>db_block_lru_latches will be set to 4. With 1 db writer, will I see
>any performance improvement at all by increasing db_block_lru_latches
>to 16 (# of cpu x 2)? Is there any relation between
>db_writer_processes and db_block_lru_latches?
>
>rgds
>Daud

db_writer_processes and db_block_lru_latches have not to do with each other. The lru_latches are latches on the buffer cache which come into play when caching a block. The only correspondence between the parameters is they are both commonly set to 2 * processors.

Hth

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Thu Aug 01 2002 - 13:00:27 CDT