Performance and concurrency are two problems that are often tightly coupled -- when concurrency grows, performance usually degrades, in some cases a lot. If you take care of performance problems, you can achieve better concurrency.
In this chapter, we will show you how to find slow queries and also 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 not covered by any of the given methods.
We will also show you how to get help in the final recipe, Reporting performance problems, in case none of the other recipes covered here work.