Some operations in SQL Server will turn your entire query plan serial (single-threaded), others will just reserve a so-called “serial zone”. I read up on this stuff a number of years ago (including a great post by Paul White), and thinking that some things must have changed since, I decided to go see for myself.
Tag: parallel
Parallel execution, part 1
The subject of parallel execution of SQL Server queries is at times somewhat shrouded in mystery and uncertainty. Since the concept of parallel execution is such a significant (and indispensable tool) for performance tuning, it’s good to have a fair idea of how it works. In this first post in a series on parallelization, I’m going to try to sort out the apples from the pears, or the serial from the parallel if you will.