What enables Parallel Query
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Thread: What enables Parallel Query

  1. #1
    Join Date
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    What enables Parallel Query

    Oracle 8.1.7.3.50

    Hi, we detected in production that some started PQ-slaves worked, were busy, but no parallel-hint is given and the degree-val of all tables is 1. so what else could cause the switch to parallel query?
    Thanks for advice
    Orca

  2. #2
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    Read the article in http://asktom.oracle.com/pls/ask/f?p...:1432298995609 , maybe is the PQ automatically being used ??

  3. #3
    Join Date
    Jan 2003
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    What is the setting of these parameters for your database:

    PARALLEL_MAX_SERVERS
    PARALLEL_MIN_SERVERS
    PARALLEL_MIN_PERCENT
    OPTIMIZER_PERCENT_PARALLEL
    PARALLEL_ADAPTIVE_MULTI_USER
    PARALLEL_AUTOMATIC_TUNING

    The following are features that will make the optimizer consider the use of a parallel plan for a query:

    * Parallel hints i.e. /*+ PARALLEL(emp,5) */ (which you don't have)
    * Parallel session setting e.g. Parameter parallel_automatic_tuning
    & parallel_adaptive_multi_user. Somebody may have set these parameters for their sessions.
    * Setting a degree of parallel and/or the number of instances on a table or index in a query.
    HTH.
    Shripad Godbole
    OCP DBA (8,8i,9i)

    "Let's document it and call it a feature."

  4. #4
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    Here the params :

    Code:
    NAME	TYPE	VALUE
    parallel_server	1	FALSE
    parallel_server_instances	3	1
    parallel_broadcast_enabled	1	FALSE
    parallel_adaptive_multi_user	1	FALSE
    parallel_threads_per_cpu	3	2
    parallel_automatic_tuning	1	FALSE
    optimizer_percent_parallel	3	0
    parallel_min_percent	3	0
    parallel_min_servers	3	0
    parallel_max_servers	3	5
    parallel_instance_group	2	
    parallel_execution_message_size	3	2152
    But i detected an index in dba_indexes which has degree of 4
    this could be the trouble-maker!
    ORca



  5. #5
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    Originally posted by JChiappa
    Read the article in http://asktom.oracle.com/pls/ask/f?p...:1432298995609 , maybe is the PQ automatically being used ??
    Thanks, in short there is all important for PQ.
    Orca

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