Performance and Concurrency
Performance and concurrency are two problems that are often tightly coupled—when concurrency problems are encountered, performance usually degrades, in some cases by a lot. If you take care of concurrency problems, you will achieve better performance.
In this chapter, you will see how to find slow queries and how to find queries that make other queries slow.
Performance tuning, unfortunately, is still not an exact science, so you may also encounter a performance problem that’s not covered by any of the given methods.
We will also see how to get help in the final recipe, Reporting performance problems, if none of the other recipes that are covered here work.
In this chapter, we will cover the following recipes:
- Finding slow SQL statements
- Finding out what makes SQL slow
- Reducing the number of rows returned
- Simplifying complex SQL queries
- Speeding up queries without rewriting them
- Discovering...