An observant person has probably noticed that SQL queries requiring disk reads not only have longer duration but also higher CPU times. It is not hard then to deduce that disk access (for both HDD and SSD), which involves the OS performing an IO call, the SQL Server process finding a place in the buffer cache for the data pages, and possibly ...

In a later blog, I want to talk about parallel execution plans. Before jumping into that topic, it is helpful to first discuss some points on interpreting execution plans. So here goes. The purpose of the cost based optimizer is to determine the best (or a very good) table access strategy in terms of which index to use or not, what join types and ...