Re: RAC is slower than non-RAC for batch job with lots of update/delete?

Hi,
It's common to see some performance impact in these cases.  The most common problem I've seen is Oracle having to do consistent reads on the blocks it's reading, therefore having to reads rollbacks segments, sometimes on the other node.
If you trace your session with RAC and without RAC you'll probably see much more gets in the RAC trace.  One way to minimize this impact is to commit more often (against common wisdom..)
Regards, Paul

----- Original Message ----
From: qihua wu <staywithpin@gmail.com>
To: oracle-l <oracle-l@freelists.org>
Sent: Thursday, October 18, 2007 7:03:01 AM
Subject: RAC is slower than non-RAC for batch job with lots of update/delete?


Hi, everyone,

After our database changed into RAC enviroment, the batch job is very slow. I am wondering whether RAC is not good for batch job. As batch job only use one session and only connect to one instance, but when update/delete data, sometime "gc current request" wait occurs as the block must be read from the other node. Without RAC, then this kind of wait will gone, so I think RAC is not good for batch job with plenty of update/delete operations. Anyone doesn't agree?


Thanks,
Qihua






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