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  1. #1
    Join Date
    Dec 2005
    Posts
    2

    Unanswered: Urgent Help required for performance tunning in ORACLE 9i.

    Hi all,

    We are loading approx. 6 crore of records into two tables of oracle 9i and then comparing those records on certain parameters.We have used all the possible indexes which can improve the performance.Still,the current performance is far below the acceptable level.Therefore we are planning to migrate to flat file level processing of data.Please give us the proc and cons of it.

    Urgent Help needed.

    Thanks & Regards,
    Kumaar s.n.

  2. #2
    Join Date
    Sep 2004
    Location
    London, UK
    Posts
    565
    Don't use indexes for full-table comparisons. Indexes are generally useful for locating relatively small numbers of rows with specific values in a large table. If you need to access all the rows they create more work. Try for full scans and hash joins, which is what I would expect the optimizer to choose once the tables are analyzed.

  3. #3
    Join Date
    Apr 2003
    Location
    Greenville, SC (USA)
    Posts
    1,155
    Without knowing the specifics, it's hard to say.... I agree with WilliamR, but
    what does the explain plan show ... how many rows in the two tables ...
    What are the wait events ... What does the buffer cache look like ... what does the query look like ... are you using parallel query ... etc ..
    You might try taking a snapshot by running statspack, run the query, take
    another snapshot and see what statspack tells you ...

    HTH
    Gregg

  4. #4
    Join Date
    Aug 2003
    Location
    Where the Surf Meets the Turf @Del Mar, CA
    Posts
    7,776
    Provided Answers: 1
    >Therefore we are planning to migrate to flat file level processing of data.
    Ready, Fire, AIM!
    You think you have a problem, but don't know what it is.
    Therefore you plan on taking a shot in the dark & hope to get lucky.
    You don't provide us (TINU) any description of the tables involved.
    You don't show us the actual SQL.
    You don't provide the EXPLAIN_PLAN.
    You fail to mention anything about table statistics.
    You expect us to rub our crystal ball & provide you a silver bullet that solves your problem.
    You're On Your Own (YOYO)!
    You can lead some folks to knowledge, but you can not make them think.
    The average person thinks he's above average!
    For most folks, they don't know, what they don't know.
    Good judgement comes from experience. Experience comes from bad judgement.

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