SQL Query Performance Tuning
Grant Fritchey · Apress eBooks · 2014
Query performance tuning remains an important part of today’s database applications. Yes, hardware performance is constantly improving. Upgrades to SQL Server—especially to the optimizer, which helps determine how a query is executed, and the query engine, which executes the query—lead to better performance all on their own. At the same time, SQL Server instances are being put on virtual machines, either locally or in hosted environments, where the hardware behavior is not guaranteed. Databases are going to platform as a service systems such as Amazon RDS and Windows Azure SQL Database. You still have to deal with fundamental database design and code generation. In short, query performance tuning remains a vital mechanism for improving the performance of your database management systems. The beauty of query performance tuning is that, in many cases, a small change to an index or a SQL query can result in a far more efficient application at a very low cost. In those cases, the increase in performance can be orders of magnitude better than that offered by an incrementally faster CPU or a slightly better optimizer.