Re: Insert contention on RAC
From: K Gopalakrishnan <kaygopal_at_gmail.com>
Date: Wed, 25 Jun 2008 15:50:35 -0500
Message-ID: <3b0f44a10806251350y28389754h65b5ec01516f8ba@mail.gmail.com>
Date: Wed, 25 Jun 2008 15:50:35 -0500
Message-ID: <3b0f44a10806251350y28389754h65b5ec01516f8ba@mail.gmail.com>
Paul,
> If I get down to log file sync, I'll be happy. The block contention is
> what's driving me nuts. And it occurs to me that if I restrict the
> inserts to one instance, I'll just get buffer busy waits instead of gc
> buffer busy waits.
This is quite interesting. What you see is a simple block contention effect amplified by the RAC.
Now to get deeper in to this one..
- Is that table partitioned? Are the waits are for segment headers or for data blocks?
- Is the table indexed? What is the contention distribution b/w tables/indexes.. You can query V$segment_statistics
- Do you have any ITL waits/Service ITL waits for that table (b. V$segment_stats)
- Are there any sequential values involved in this business transaction?
-- Best Regards, K Gopalakrishnan Co-Author: Oracle Wait Interface, Oracle Press 2004 http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/ Author: Oracle Database 10g RAC Handbook, Oracle Press 2006 http://www.amazon.com/gp/product/007146509X/ -- http://www.freelists.org/webpage/oracle-lReceived on Wed Jun 25 2008 - 15:50:35 CDT