Sitecore Performance SQL Server Tip
Parallelism is a feature in SQL Server which allows expensive queries to utilize more threads in order to complete quicker. The query optimizer makes the determination of how expensive a query is based upon the Cost Threshold for Parallelism setting set at the SQL Server Instance level. This cost threshold for parallelism is an estimate (roughly defined in seconds) that the query optimizer has determined a statement will take based on an estimated (or cached) execution plan.
To enable the server to determine the maximum degree of parallelism, set this option to 0, the default value. Setting maximum degree of parallelism to 0 allows SQL Server to use all the available processors up to 64 processors.
To suppress parallel plan generation, set max degree of parallelism to 1.
Set the value to a number from 1 to 32,767 to specify the maximum number of processor cores that can be used by a single query execution. If a value greater than the number of available processors is specified, the actual number of available processors is used. If the computer has only one processor, the max degree of parallelism value is ignored.
Please make sure it(maximum degree of parallelism) has proper value otherwise it will impact performance of your web application.
