Thanks for the information. I don't know why I have not already found this page. For the record:
* Resource Governor is not running
* Server CPU load is less than 1 of 8 cores
* Statistics of the data are extremely similar in the test environment and the production environment (it is a copy of the production database).
In the test environment is maxdop configured to 4 on the instance level however, and here the index was created in parallel. This is still a mystery to me, but it appears that SQL Server somehow has found a reason to decrease degree of parallelism for the index creation to 1.
Also from BOL:
"When the Database Engine builds an index execution plan, the number of parallel operations is set to the lowest value from among the following:
The number of microprocessors, or CPUs in the computer.
The number specified in the max degree of parallelism server configuration option.
The number of CPUs not already over a threshold of work performed for SQL Server threads."
[font="Arial"]“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw[/font]
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