答复: excessive number of db writer

From: Serol_Luo \(BJ\) <Serol_Luo_at_smics.com>
Date: Wed, 6 Sep 2006 17:08:47 +0800
Message-ID: <B1B44026C565CF4F9753E28AAFB123CD01856F@bjex108.smic-bj.com>

Maybe 2-statspack reports can help to measure if the change of DB-Writers has any effect on database performance. 1 before change, 1 after change  

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Regards.
Serol Luo
SMIC / BJ-IT / SDBS
(010-)6785-5000 Ext:21012  

-----原始邮件-----
发件人: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]代表 K Gopalakrishnan 发送时间: 2006年9月6日 17:05
收件人: ax.mount_at_gmail.com; oracle-l_at_freelists.org 主题: Re: excessive number of db writer  

Alex,

Did you get an explanation for those suggestions? It would be difficult for us to comment on those changes without any additional details..

However, However,However, 20 DBWriters are certainly high for your configuration ;)  

Have a nice day !!

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Best Regards,
K Gopalakrishnan,
Co-Author: Oracle Wait Interface: Oracle Press 2004. http://www.amazon.com/gp/product/007222729X/

Coming Soon: Oracle RAC Handbook, Oracle Press 2006 http://www.amazon.com/gp/product/007146509X/  

• Original Message ---- From: amonte <ax.mount_at_gmail.com> To: oracle-l_at_freelists.org Sent: Wednesday, September 6, 2006 1:39:51 AM Subject: excessive number of db writer

Hi

I have been suggested by some Oracle Consultant to set 20 Database Writer in a 12 CPU HP-UX Server.

Does anyone know what are the side effects of having excessive DBWR? I detected a higher CPU usage (between, 1% to 2%) not sure if its due to the number of Database Writer. Because when I increased the number of DBWR at init.ora I also changed these parameters

_row_cache_cursors = 60
_kgl_latch_count = 59
_kghdsidx_count = 4

statistics_level = basic

again suugested by this guy.

TIA Alex  

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Received on Wed Sep 06 2006 - 04:08:47 CDT