Insert contention on RAC
- From: "Baumgartel, Paul" <paul.baumgartel@xxxxxxxxxxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Wed, 25 Jun 2008 15:18:39 -0400
To borrow the style from some MetaLink notes--
Fact: Oracle 10.2.0.1.0
Fact: RedHat 3
Fact: 3 node RAC
Many concurrent sessions inserting one row at a time into the same
table. On first run, table in ASSM tablespace, about 50% of database
service time was gc buffer busy waits. Built a new tablespace with
manual segment management, re-created table with three freelist groups
and 4 freelists. Next run showed >90% of service time was enq: HW
contention; total run time was slightly higher than it was with ASSM..
Re-created table again, allocated three 4 GB extents, one for each
instance. Current run is still showing high HW contention waits.
Might I have too many freelists? Other than forcing all sessions to use
the same RAC instance, is there anything else I can do to reduce these
waits?
Thanks,
Paul Baumgartel
CREDIT SUISSE
Information Technology
Prime Services Databases Americas
One Madison Avenue
New York, NY 10010
USA
Phone 212.538.1143
paul.baumgartel@xxxxxxxxxxxxxxxxx
www.credit-suisse.com
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