Lock issues are one of the common causes of performance issues, and the impact can be severe. In the worst cases, queries can fail, and connections pile up so no new connections can be made. Therefore, it is important to know how to investigate lock issues and remediate the problems.
This and the following chapters will discuss six categories of lock issues:
Flush locks
Metadata and schema locks
Record-level locks including gap locks
Deadlocks
Foreign keys
Semaphores
Apart from the foreign keys case study, each category of locks uses different techniques to determine the cause ...
