Limiting number of parallel query slaves
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Thread: Limiting number of parallel query slaves

  1. #1
    Join Date
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    Limiting number of parallel query slaves

    Hi Guys,

    Is it possible to limit the amount of parallel query slaves spawned per user?

    I have parallel_max_servers set to 64, but the first user can sometimes spawn all 64!! which means that everyone else runs in serial mode.

    I've got memory usage pinned by pga_aggregate_target on a windows box, so I don't run into 'out of memory process' issues.

    Thanks.

  2. #2
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    I don't think you can limit this per-session.
    Jurij Modic
    ASCII a stupid question, get a stupid ANSI
    24 hours in a day .... 24 beer in a case .... coincidence?

  3. #3
    Join Date
    Sep 2000
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    Sao Paulo,SP,Brazil, Earth, Milky Way
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    afaik no, you canīt set a limit for each user, what tou can do is :

    - set a (small) degree for each table involved

    or

    - use PARALLEL_ADAPTIVE_MULTI_USER, with this the first user will NOT be able to use all the slaves, some will be reserved, and in the future, with new users trying to do parallel things, more slaves will be "removed" from the first user. But this algorithm is CLOSED, you canīt change it, you canīt specify what portion os slaves to each user...

    Regards,

    Chiappa

  4. #4
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    Nov 2006
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    You can use Resource manager to limit the number of px slaves per consumer group.
    You can modify that to a case where the consumer group has one user only and hence limit px slaves per user

    Regards
    Boris

  5. #5
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  6. #6
    Join Date
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    Thanks Guys,

    Gonna look at PARALLEL_ADAPTIVE_MULTI_USER

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