Parallelism

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Parallelism

kevin_nikolai

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November 3, 2008 at 2:53 pm

#195643

SQL Server 2005:
Server Properties, Parallelism
Query wait:
the default value of -1 means the time is calculated as 25 times of the estimated query cost
Question: When will you use Parallelism, please give a few examples ?
Is it a good idea to use it ?
Regards
Kevin
sonyt65@yahoo.com

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SanjayAttray SSChampion Points: 13157 More actions · Answer 1

http://blogs.msdn.com/craigfr/archive/2006/10/25/the-parallelism-operator-aka-exchange.aspx

http://blogs.msdn.com/craigfr/archive/2006/11/16/parallel-hash-join.aspx

And here is a good article about parallelism in sqlservercentral.

http://www.sqlservercentral.com/articles/Configuring/managingmaxdegreeofparallelism/1029/

Also, see the discussion on this article.

SQL DBA.

Jonathan Kehayias One Orange Chip Points: 26778 More actions · Answer 2

For the most part, leaving the optimizer to control when to use parallelism is the best thing. There are instances where you get waits that are parallelism introduced, and using the MAXDOP option is better for performance.