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  1. #1
    Join Date
    May 2010
    Posts
    8

    Unanswered: Replicated MQT - Refresh Deffered

    Hello All,

    I create a replicated MQT table on top of a base table with refresh deffered.The base table has 109 col and the MQT has 16 cols.Now from what i read in articles is that we create MQT and indexes on it.We give base table name in the queries and the db2 optimizer will decide which table to take (base table or MQT).My question here is what if i give the MQT directly in the query instead of the base table?? Will it effect the performance????

    Please let me know
    Thanks,

  2. #2
    Join Date
    Jan 2003
    Posts
    4,292
    Provided Answers: 5
    You will read from the MQT. Assuming that you have the appropriate indexes and all, it should perform well.

    Andy

  3. #3
    Join Date
    May 2010
    Posts
    8
    Thanks Andy...So it should work well and it keeps the db2 optimizer out of the decision making....

  4. #4
    Join Date
    Jan 2007
    Location
    Jena, Germany
    Posts
    2,721
    Yes, that's correct. If you query the MQT, the optimizer won't route to the base table - it only works in the opposite direction.
    Knut Stolze
    IBM DB2 Analytics Accelerator
    IBM Germany Research & Development

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