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## Note 

The preceding result set includes wait event data produced during the startup process. To exclude this data, you can truncate the events_waits_summary_global_by_event_name  table immediately after startup and before running your workload. However, the truncate operation itself may produce a negligible amount wait event data. 

mysql> TRUNCATE performance_schema.events_waits_summary_global_by_event_name; 

## 15.17 InnoDB Monitors 

InnoDB  monitors provide information about the InnoDB  internal state. This information is useful for performance tuning. 

## 15.17.1 InnoDB Monitor Types 

There are two types of InnoDB  monitor: 

•The standard InnoDB  Monitor displays the following types of information: 

•Work done by the main background thread 

•Semaphore waits 

•Data about the most recent foreign key and deadlock errors 

•Lock waits for transactions 

