Update's very slow
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Thread: Update's very slow

  1. #1
    Join Date
    Jan 2002
    Posts
    22
    Hi all,
    I translate statements From SQLServer To
    Oracle ,
    In SQLSERVER :

    Update A
    set ...
    FROM conditions

    in Oracle this statement is very slow :

    Update A
    set ... =
    (select ..)
    where conditions and Exists (select ...);

    Who know an optimization for this ?

    Thanks in avance.






  2. #2
    Join Date
    Nov 2000
    Location
    greenwich.ct.us
    Posts
    9,092
    The short answer is use an index.

    The long answer is: Depends, what's the query plan say?
    Jeff Hunter
    marist89@yahoo.com
    http://marist89.blogspot.com/
    Get Firefox!
    "I pledge to stop eating sharks fin soup and will not do so under any circumstances."

  3. #3
    Join Date
    Nov 2000
    Location
    Baltimore, MD USA
    Posts
    1,339
    Yeah, some more information would be helpful towards crafting a better statement.

    You will find this to be one of the more painful parts of a conversion from SQLServer to Oracle - Oracle, quite frankly, sucks at multi-table updates, whereas SQLServer handles them very eloquently.

    Give us an actual statement (and plan, preferably) and we'll see what we can do for you.

    - Chris
    Christopher R. Long
    ChrisRLong@HotMail.Com
    But that's just my opinion. I could be wrong

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