Performance using CTE vs temp tables

• npranj

  SSCrazy

  Points: 2323

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  December 13, 2012 at 5:36 am

  #286095

  Hi All,

  I have replaced 3 temp tables in my batch with multiple CTEs.

  I see remarkable 50% benefit in REads and Writes have reduced to 0, however, I wanted to know on the CPU.

  Is CTE CPU Intensive? I am getting varying CPU results.

  Also, I see from other questions that CTEs hit performance when table size is v great. Is that so?

• Jeff Moden

  SSC Guru

  Points: 1004588

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  December 13, 2012 at 8:23 pm

  #1568540

  nidhis (12/13/2012)

  ---

  Hi All,

  I have replaced 3 temp tables in my batch with multiple CTEs.

  I see remarkable 50% benefit in REads and Writes have reduced to 0, however, I wanted to know on the CPU.

  Is CTE CPU Intensive? I am getting varying CPU results.

  Also, I see from other questions that CTEs hit performance when table size is v great. Is that so?

  "It Depends" on what the Temp Tables are being used for and how they are being used. Just like views and derived tables, CTEs can be quite good at performance and quite bad.

  --Jeff Moden

  ---

  RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
  First step towards the paradigm shift of writing Set Based code:
  ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

  Change is inevitable... Change for the better is not.
  

  ---

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  How to Post Performance Problems
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