Understanding parallelism on SQL Server

Parallelism refers to multiple processors cooperating to execute a single query at the same time. Parallel execution involves the overhead of synchronizing and monitoring the tasks. So, that's why parallel┬áplans are considered expensive operations. The query optimizer determines whether a parallel plan should be used based on the configuration and the query cost. A configuration … Continue reading Understanding parallelism on SQL Server

SQL Server threads architecture

SQL Server retrieves threads from Windows. The SQL Server configuration setting max worker threads (set at instance level) determines how many threads will be retrieved. SQL Server has its own internal scheduling system, independent of the scheduling performed by the operating system. Instead of using Windows threads directly, SQL Server creates a pool of worker … Continue reading SQL Server threads architecture