RE: Increasing Freelists?

Hi Jay,
 If the table(s) need(s) to support multiple concurrent insert operations from multiple transactions and you are seeing a lot of buffer waits then adjusting freelists may help you. Setting it up to a max of twice the number of CPUs should work (provided that the number of CPUs is not tool high, say, more than 20). Setting it too high will potentially increase the high water mark for the table. This is because how oracle inserts blocks (5 at a time) into each free list. If you are using Oracle 8.1.6 or 8.1.7, please check a Note # 76644.1 on Metalink. Per that note, it is possible to change freelist parameter on existing table. If your are not using OPS setup, you can ignore Freelist Groups. Note # 1029850.6 provides some good info to understand these parameters.

Hope this helps.

Regards,

• Kirti Deshpande Verizon Information Services http://www.superpages.com

> -----Original Message-----
> From: Miller, Jay [SMTP:JayMiller_at_TDWaterhouse.com]
> Sent: Friday, June 15, 2001 2:31 PM
> To: Multiple recipients of list ORACLE-L
> Subject: Increasing Freelists?
>
> We've been load testing an application that will be allowing customers to
> enter their email information through the web. The loadrunner application
> was experiencing periodic freezing after which it would go back to normal.
> Reviewing the statspack information I saw a high number of buffer busy
> waits
> with the majority of the buffer waits being data block waits. This is not
> surprising, since the application is doing heavy inserts into several
> tables.
> The recommendation from an article I have is to create multiple freelists
> for the tables undergoing heavy inserts. I've never done this before and
> I
> have no idea of how many to create. Increase the freelists from 1 to 2?
> More? What about freelist groups?
>
> And am I correct that the table must be dropped and recreated to increase
> this parameter?
>
> I was hoping to have read Gaja's book before I had to deal with this but
> it's still in the mail :).
>
> Thanks in advance.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Miller, Jay
> INET: JayMiller_at_TDWaterhouse.com
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Deshpande, Kirti
  INET: kirti.deshpande_at_verizon.com

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