When is ‘AUTOMATIC’ Not STMM?

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4 Responses

  1. Ian Bjorhovde says:

    A couple of notes: STMM requires at least 2 memory consumers to be enabled for STMM to do anything. Also, when IBM introduced STMM, IBM started using the term COMPUTED for memory areas it calculates at startup and changed AUTOMATIC to mean STMM.

  2. isaac munoz says:

    Hi Ember, great article!!

    What happens when you got multiple db2 instances on a single server and all of them have INSTANCE_MEMORY=AUTOMATIC & DATABASE_MEMORY=AUTOMATIC ?. Is DB2 smart enough to never cause the server swap to disk?. Does it apply in all DB2 LUW supported platforms?

    Regards

    • Ember Crooks says:

      Since nearly all of my production servers are single instance to single server implementations, I don’t have direct experience here. I believe IBM would tell you yes, but this is one area I have heard of significant issues in from other DBAs. I know some respected DBAs who don’t like setting instance and database memory to automatic on multi-instance implementations, so my initial reaction would be to to avoid that. It would be an interesting question to ask Scott Hayes (who runs the db2Night show).

  1. July 15, 2014

    […] with, it is important to understand what STMM tunes and what it doesn’t. I recommend reading When is ‘AUTOMATIC’ Not STMM?. There are essentially only 5 areas that STMM can […]

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