Redo latch tuning question

From: Anne Hanson <ahanson_at_fas.harvard.edu>
Date: Fri, 01 Oct 1999 10:45:47 -0400
Message-ID: <37F4C91B.E1FEC77A@fas.harvard.edu>

On one of my servers, I have heavy contention for redo copy latches. The gets/misses ratio is extremely poor. The immediate gets/misses ratio is fine. The redo allocation latch is not experiencing any contention. I'm running 8.0.5 on NT 4.0. I've been reading up on latches, and the two solutions I've seen suggested are:

Increase the LOG_SIMULTANEOUS_COPIES initialization parameter to 2 * number of CPUs. Right now it is 2, as the server has 2 CPUs.
If the above doesn't help, increase the LOG_SMALL_ENTRY_MAX_SIZE so more redo entries will be handled by the redo allocation latch.

Does anyone know of any down side to either of these solutions, or anything else I should be thinking of? Thanks in advance for any tips,

Anne Received on Fri Oct 01 1999 - 09:45:47 CDT