Parallelism in Microsoft SQL Server - Torsten Strauß

SQL Server can execute queries in parallel which can sometimes improve the performance of your queries. However, parallelism has its own challenges; therefore, we will look at the concept of parallel executions to understand when it makes sense to run a query on more than one thread. We deal with topics such as CXPacket, threads, workers, execution context, branches, MAXDOP, Cost threshold for parallelism, NUMA nodes and the iterators that SQL Server can implement in the execution plan to enable parallelism.