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Wednesday, August 24, 2011

Maximum number of supported nodes in a cluster


http://support.microsoft.com/kb/288778

OR

Differene between affinity mask and max degree of parallelism

Affinity mask is instance level configuration
Degree of Parallelism is Query level configuration
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If you have Multiple physical processors or logical Cores in your machine .It is very easy to understand the benefit of Afinitymask.For example u have 4 cores and 2 instances in your machine then ,u can share processors for each instance like 2 cores per instance.(for better resource balance).


Maxdop is for query execution purpose. By default it will be on for all processors.(All processors will work on one query execution).You can change this behavior for particular query like alter index .for ex if u give maxdop =2 while executing query ,2 processors will dedicated for this query execution where as other processors can handle server work load.