Performance Schema Event Timing
Events are collected by means of instrumentation added to the server source code. Instruments time
events, which is how the Performance Schema provides an idea of how long events take. It is also
possible to configure instruments not to collect timing information. This section discusses the available
timers and their characteristics, and how timing values are represented in events.
Two tables provide timer information:
• performance_timers lists the available timers and their characteristics.
• setup_timers indicates which timers are used for which instruments.
Each timer row in setup_timers must refer to one of the timers listed in performance_timers.
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