SQL Server Performance

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Discussion in 'SQL Server DTS-Related Questions' started by srikale, Nov 7, 2003.

  1. srikale New Member

    Hi
    i have a question on Exporting an indexed table to a flat file


    I have a Table A which is Indexed and another Table B without any indexes.

    I am Exporting Table A to Flat file1 and Exporting Table B to Flat file 2
    Which one is faster? Indexed table Or Non Indexed Table

    Thanks in Advance
    Srinivas

  2. satya Moderator

    I think Indexed one would be faster as data is arranged and if you're simply exporting without any query conditions.
    (to be frank I haven't tested this but can confirm based on indexing advantages, would like to hear fellow peers)

    _________
    Satya SKJ
    Moderator
    SQL-Server-Performance.Com
  3. ChrisFretwell New Member

    With just the little information there, I dont know on this one. The export speed itself would be constant in how fast it can write to your disk system, for either table.
    If you are just exporting with something like select * from tablea or select * from tableb, then you can take a quick check in QA for the estimated query plan to see if there is any expected performance difference.
    And if you are putting criteria on the select, or an order by that would make use of the index, then using the indexed table will be faster. Again, this is easy to check by looking at both query plans in QA.
    Flat files themselves dont store indexes, so to the output file itself, there is no difference. Its all in the select.

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