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  1. #1
    Join Date
    Sep 2008
    Posts
    4

    Unanswered: Load data in four threads.

    Hello,

    I try load data in four threads (in one time):

    thread 1:

    SET PDQPRIORITY 25;
    Load from 'data1.unl' insert into tableA;

    thread 2:

    SET PDQPRIORITY 25;
    Load from 'data2.unl' insert into tableB;

    thread 3:

    SET PDQPRIORITY 25;
    Load from 'data3.unl' insert into tableC;

    thread 4:

    SET PDQPRIORITY 25;
    Load from 'data4.unl' insert into tableD;


    but informix not using PDQ:

    onstat -g mgm

    ################################################## #

    Memory Grant Manager (MGM)
    --------------------------

    MAX_PDQPRIORITY: 100
    DS_MAX_QUERIES: 60
    DS_MAX_SCANS: 1048576
    DS_NONPDQ_QUERY_MEM: 128 KB
    DS_TOTAL_MEMORY: 6291456 KB

    Queries: Active Ready Maximum
    0 0 60

    Memory: Total Free Quantum
    (KB) 6291456 6291456 104856

    Scans: Total Free Quantum
    1048576 1048576 1

    Load Control: (Memory) (Scans) (Priority) (Max Queries) (Reinit)
    Gate 1 Gate 2 Gate 3 Gate 4 Gate 5
    (Queue Length) 0 0 0 0 0

    Active Queries: None

    Ready Queries: None

    Free Resource Average # Minimum #
    -------------- --------------- ---------
    Memory 0.0 +- 0.0 786432
    Scans 0.0 +- 0.0 1048576

    Queries Average # Maximum # Total #
    -------------- --------------- --------- -------
    Active 0.0 +- 0.0 0 0
    Ready 0.0 +- 0.0 0 0

    Resource/Lock Cycle Prevention count: 0

    ################################################## #

    What is the reason ?

  2. #2
    Join Date
    Feb 2009
    Posts
    51
    Database Server Operations That Use PDQ
    About insert:
    The database server performs the following types of inserts in parallel:
    * SELECT...INTO TEMP inserts using explicit temporary tables.
    * INSERT INTO...SELECT inserts using implicit temporary tables.

    I think that constraction Load from ... insert into ... does not support PDQ.
    Use HPL for fast unload/load to/from file.

  3. #3
    Join Date
    Jun 2005
    Location
    Santa Fe, Argentina
    Posts
    27
    Hi, PDQ is used in certain situations, like index creations, select in fragmented tables, or in joins querys, or when using some aggregations funcions. I agree with rootdbs, for faster load, use HPL.

  4. #4
    Join Date
    Sep 2008
    Posts
    4
    OK, thanks !!!

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