SQL Server 2022 Query Performance Tuning: Troubleshoot and Optimize Query Performance

© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2022

G. FritcheySQL Server 2022 Query Performance Tuninghttps://doi.org/10.1007/978-1-4842-8891-7_5

5. Statistics, Data Distribution, and Cardinality

Grant Fritchey¹  

(1)

Grafton, MA, USA

 

In Chapter 2, we talked about the query optimization process and how it uses the indexes, constraints, and other objects within your database in order to figure out how best to satisfy the query. All those objects in combination are how the optimizer arrives at its estimated values. However, one of the single biggest driving factors in what leads the optimizer to choose one method of query behavior over another is row counts. Since SQL Server can’t count all the rows ahead of ...