Log Buffers

Hi There,

    I'm trying to work out if the size of my log buffers is too large. I cant
    find a reference in the FAQ for this but memory (In my case 3 active
    nuerons - 2 of which arent talking to each other) indicates that I can
    work this out from logstat output by:

    %Log Buffer Used = KBytes Written / 
                        (Log Write i/o's * Size of Log Buffer(k))

    Is this correct?

    The reason I'm asking is that I have to support a 3rd party product that
    manages to blow a 500M log file from only a 100M database. I suspect the
    vendors have either:
    1. Never heard of the word 'commit', or
    2. Like to do a lot of row by row processing.

    I suspect both.

    My current Log buffer size is 8k. And if the above formula is correct then
    I'm using less than half the buffer (47%) and could reduce to 4k Buffers.
    This would hopefully mean I could retain the 500M log and not have to
    remain at my new 750M log.

    Martin Bowes.

Martin,

Your calculation is correct.  Remember to monitor log split waits.
Also, you may need to increase the total number of log buffers
(better to have too many than not enough).

Chip Nickolett              ChipN@CaribouLake.com
Caribou Lake Software  http://www.CaribouLake.com  Java/RDBMS Solutions
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