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Home -> Community -> Mailing Lists -> Oracle-L -> Re: BLOCK_BUFFERS_KEEP
Hi,
The init.ora parameter to set buffer pool keep and recycle is
BUFFER_POOL_KEEP = (BUFFER:<int>,[LRU_LATCHES:<int>])
BUFFER_POOL_RECYCLE = (BUFFER:<int>,[LRU_LATCHES:<int>])
There has to be a minimum of 50 buffers for each LRU latch, like minimum buffers should be 150 if latches are 3.
When the object is created, you can indicate buffer_pool keep as part of the storage clause and the object when read first time will be kept in the buffer cache keep pool.
In a nutshell, to determine the buffers, check to see objects that are required to be cached for the keep pool. According to tuning manual, any object that consumes 1% of the I/O and constitutes 10% of the buffer cache is a good canditate for keep pool. We found the buffers byt finding out how much buffer busy waits we had and then we figured out the segment that needs to be cached and also segments that needed to be recycled.
Refer to the tuning manual for a detailed explanation on sizing your buffer pool and also determining canditates to be placed in each of the pools.
Hope this helps.
Regards,
Madhavan
IBM Corporation Webserver Div
>From: "Blum, Marc" <blum_at_soptim.de>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: BLOCK_BUFFERS_KEEP
>Date: Thu, 18 May 2000 23:06:37 -0800
>
>Dear all,
>
>does anyone know the correct syntax for the parameter BLOCK_BUFFERS_KEEP.
>The example provided in oradoc (BLOCK_BUFFERS_KEEP = (buffers:400,
>lru_latches:3"') ) seems to be incorrect. Further: any suggestions how much
>buffers and lru_latches to start with?
>
>bye
>marc
>
>__________________________
> Marc Blum
> SOPTIM GmbH
> Grüner Weg 22-24
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>
>
>--
>Author: Blum, Marc
> INET: blum_at_soptim.de
>
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