High Number of undo writes

  • From: Purav Chovatia <puravc@xxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Tue, 15 May 2012 21:10:23 +0530

We are running a workload on 2 different setups to compare performance. And
we have some very unusual observations for exactly the same workload.
There are a few differences between the 2 setups, but none of those are
able to justify the difference.

I will provide more details later (sorry but got to leave), but one major
difference is that setupA runs whereas setupB runs And
the observation is that in B, the no. of writes to undo tablespace is
comparatively very high (Av writes/s is 57 in A and 854 in B). Is this
observed previously by anybody? There are other unusual differences but
those seem to be because of these high undo writes.



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