SQL Server Performance

Reordering Joins for Performance Gains

Discussion in 'T-SQL Performance Tuning for Developers' started by Ryzor, Jul 8, 2005.

  1. Ryzor New Member

    Everything else being equal....have you ever reordered the joins in a TSQL SELECT statement to optimize performance? I have a working hypothesis that the order of the joins will determine the execution plan that it uses. Still testing...haven't reach a final conclusion yet.
  2. mmarovic Active Member

    Yes, many times. To make join order relevant you have to use query hint force order.
  3. joechang New Member

    the join order in your statement should not influence the actual execution plan if the statements can be determined to be equivalent
    unless you use a join hint, or other hint,
    execption being when the query is so complicated that it triggers the optimizer's governor on when to given up searching alternate plans,
    but this requires many joins and many indexes

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