The parallel extension to the from clause of a select command allows users to suggest the number of worker processes used in a select statement. The degree of parallelism that you specify cannot be more than the value set with sp_configure or the session limit controlled by a set command. If you specify a higher value, the specification is ignored, and the optimizer uses the set or sp_configure limit.
The syntax for the select statement is:
select ...
from tablename [( [index index_name]
[parallel [degree_of_parallelism | 1 ]]
[prefetch size] [lru|mru] ) ] ,
tablename [( [index index_name]
[parallel [degree_of_parallelism | 1]
[prefetch size] [lru|mru] ) ] ...
