Are tabular udfs helpful or hurtful?

• Eric M Russell

  SSC Guru

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  October 27, 2010 at 10:09 am

  #1243021

  Looking at the Actual Execution Plan of the query may not tell you the internals of what the UDF is doing, but it should give you an idea of how much the join is costing you relative to the batch. If that doesn't help, or if you determine the UDF is the bottleneck, then try pulling the SQL out of the UDF and constructing a simplified version of the query that returns the same columns but joins straight to the tables. Sometimes deconstructing a problem one level at a time helps identify the solution.

  "Do not seek to follow in the footsteps of the wise. Instead, seek what they sought." - Matsuo Basho