Results 1 to 4 of 4
  1. #1
    Join Date
    Sep 2011
    Location
    Australia
    Posts
    264
    Provided Answers: 2

    Unanswered: Queries -Order of rules and speed.

    While the current posts are focused on queries I was wondering if any member has done any testing as to the effect of the order of multiple rules (and/or) on speed? As example searching a customer form for male/female ( likely 50/50) and age over 100 (likely 1 in 1000+). Does the engine locate half the records then check all these for age (many thousands) or if age placed first (may be 100 persons), only a few records to check for male/female.
    Will experiment if no one tried this out. Just need time to build a large file to push BD to limits ( 100,000+ records should show up any effect).
    Regards
    David
    Last edited by tamcind; 06-30-14 at 07:39.

  2. #2
    Join Date
    Jul 2012
    Location
    Ireland
    Posts
    815
    Provided Answers: 17
    Just messing around here with a test file that's just shy of 1 million records.

    It seems to make no difference what order the query was written. It takes 3 seconds to process the records anyway I try it, and return 90,000+ results.

    Tested on an 8 core Alienware laptop overclocked to 4Ghz with 32GB of RAM, but it seems it makes little difference as the CPU load never peaks over 25% for some odd reason.

    Regards
    James

  3. #3
    Join Date
    Sep 2011
    Location
    Australia
    Posts
    264
    Provided Answers: 2
    Thanks James
    Just crossed my mind that we should check this out incase there was a speed issue. I believe Sql databases often use query optimisation but the circumstances are a bit different (no table joins for one) but with no help from BD the only way seems to test it ourselves.
    Regards
    David

  4. #4
    Join Date
    Jul 2012
    Location
    Ireland
    Posts
    815
    Provided Answers: 17
    Yeah sure, it was well worth the effort to test. I didn't think it would run that fast myself on a million records.

    Regards
    James

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •