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  1. #1
    Join Date
    Feb 2006
    Posts
    2

    Question Unanswered: UDB - Export Utility Performance

    Our system is on UDB 8.1 and we are using this command to export the data to a file....

    time db2 "export to <file_name> of del modified by coldel@ select * from <table_name> where clause with ur"

    while this runs, we monitored the file size change. File size increase stopped after 7min. But the utility reponded after 20min. Any idea what was the export utility doing for 13minutes after the file is created with records in the first 7min.

    Apprepiate ur replies..

    Thanks,
    Nagesh

  2. #2
    Join Date
    Aug 2001
    Location
    UK
    Posts
    4,650
    Are you doing a join of two tables ? Or is it a single table query as your example shows ?

    In the former case, it may be that in the first 7 minutes, it had selected x number of records while still performing joins ... It wouldn't have been able to find a matching row for the next 13 mins .. (Poor performance, but theoretically possible)

    In the latter case, it is not a 'normal' thing

    Cheers
    Sathyaram
    Visit the new-look IDUG Website , register to gain access to the excellent content.

  3. #3
    Join Date
    Feb 2006
    Posts
    2
    hmm, good thought. It is a single table query though.

    where clause is on a field which is indexed. Don't know if the utility is doing table scan instead of using the index. Is there a way we can check the access path of the export utility?

    -- Nagesh

  4. #4
    Join Date
    Aug 2001
    Location
    UK
    Posts
    4,650
    Use the usual explain tools on the select stmt .

    Sathyaram
    Visit the new-look IDUG Website , register to gain access to the excellent content.

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