Re: Insert contention on RAC

From: K Gopalakrishnan <>
Date: Wed, 25 Jun 2008 15:50:35 -0500
Message-ID: <>


> 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..

  1. Is that table partitioned? Are the waits are for segment headers or for data blocks?
  2. Is the table indexed? What is the contention distribution b/w tables/indexes.. You can query V$segment_statistics
  3. Do you have any ITL waits/Service ITL waits for that table (b. V$segment_stats)
  4. Are there any sequential values involved in this business transaction?
Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004

Author: Oracle Database 10g RAC Handbook, Oracle Press 2006
Received on Wed Jun 25 2008 - 15:50:35 CDT

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