Re: MVS and large database

Brian McCabe wrote:
> The site I am working at is also experiencing problems with Oracle
> performance on MVS. We are planning to migrate from AIX to MVS and
> although the database only currently stands at less than 100Gb, we
> intend to reach pretty near to the 1Tb figure next year.
>
> Initial performance of Oracle on MVS is very disappointing and no
> obvious bottle-neck has been determined to date. The Orace Instance is
> idling, the network is not under any great stress and the MVS-Gurus tell
> us that nothing is pushing the operating system or disk IO sub-system.
>
> A question for Bill - is there a repository of information on tuning
> Oracle for MVS anywhere which contains information which is not in the
> Oracle/MVS SYS Admin Guides? We have followed these instructions to the
> letter and performance is still at least three times as poor as on the
> AIX Box.
>
> Can anyone else offer any pointers in the right direction????

Please excuse my ignorance but...

If the cpu and i/o subsystem are underloaded then you might be queueing on something else either at the o/s, network, or database levels. I haven't done any MVS work for a while but can you set the number of worker tasks (in unix they're shadow processes that access the database for the client) higher so that more connections are active concurrently. Have you confirmed that there is no internal database lock contention. Are all your interactive and batch processes running at the same cpu priority. Is your database SGA too large and being paged out of real memory.

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   T T T T T T T T        Bruce Pihlamae
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