Memory Performance Analysis

Abstract

A system can directly impact SQL Server and the queries running on it in three primary places: memory, disk, and CPU. You’re going to explore each of these in turn starting, in this chapter, with memory. Queries retrieving data in SQL Server must first load that data into memory. Any changes to data are first loaded into memory where the modifications are made, prior to writing them to disk. Many other operations take advantage of the speed of memory in the system, such as sorting data due to an ORDER BY clause in a query, performing calculations to create hash tables when joining two tables, and putting the tables in memory through the in-memory OLTP tables functions. Because all this work is being done within the memory of the system, it’s important that you understand how memory is being managed.