Most Popular Parallel Operations

Why SQL Server May Not Parallelize a Query

You may see cases when you have an expensive-enough query that is not parallelized. There are several SQL Server features that inhibit a parallel plan creating a serial plan instead: Scalar-valued user-defined functions. CLR user-defined functions with data access. Miscellaneous built-in functions such as OBJECT_ID(), ERROR_NUMBER(), and @@TRANCOUNT. Dynamic cursors. In a similar way, there […]

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