Maxdop query

• BLOB EATER

  SSChampion

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  December 16, 2015 at 8:19 am

  #314252

  hi SQL family,

  which statement regarding maxdop is true as I am slightly confused...

  1)MAXDOP limits the number of logical processors that can be used for a given query?

  2)MAXDOP constrains the number of threads per operator within the query?

• Alan Burstein

  SSC Guru

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  December 16, 2015 at 9:25 am

  #1846354

  MAXDOP restricts the number of CPUs that can be used in a parallel query plan. MAXDOP 0 let's SQL Server use as many as SQL Server wants (up to 64 CPUs).

  "I cant stress enough the importance of switching from a sequential files mindset to set-based thinking. After you make the switch, you can spend your time tuning and optimizing your queries instead of maintaining lengthy, poor-performing code."

  -- Itzik Ben-Gan 2001