If you don't actually have a multiprocessor machine on which you can test the
code in the main article, that doesn't mean that you'll never see a DegreeOfParallelism
greater than one. You can simulate multiple processors by using a special flag
when you start SQL Server. To do so, in SQL Server Configuration Manager, expand
the node for SQL Server 2005 Services. Right-click your SQL Server service and
choose Properties. On the Advanced tab, expand the Startup Parameters value, and
add -Pn after the last parameter, where n is a number greater than
1, to tell SQL Server to start up n schedulers, as Figure
A shows. (I frequently use -P4.) Be sure to add a semicolon after the last
parameter on the line, and don't leave any spaces after the semicolon or between
the dash and the P. Click Apply, then start or restart your SQL Server service.
Of course, you should never use this technique on a production machine; it's only
for examining query plans for parallel queries, not for actually seeing the performance
impact of parallel queries.