CTFP vs Processor time vs Lazy writes.

• mig28mx

  Ten Centuries

  Points: 1090

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  October 23, 2018 at 12:36 pm

  #409138

  Hi,
  Recently I have changed the value of Cost Trheshold for Paralelism from 5 (defalut) to 15, due to I have checked that value is greater than the maximum subtree cost for all the queries that going on parallel. This is much less than the Microsoft´s recommendation 50 and less than the rule of thumb for this value that I found in some forums, that is 25.
  After changing this value I have noticed that the Overall Processor Time have been droped from 40% average utilization to 15% average utilization, that I believe it is a good gain. However, I Also I have noticed that before this change, the lazy writes rarely occured. But after the change, the lazy writes shows up almos daily with low values.

  My question is: it is best to have a low processor time vs get often lazy writes?

  Thank you in advance.