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Instance tables document what types of objects are instrumented. They provide event names and explanatory notes or status information:

These tables list instrumented synchronization objects, files, and connections. There are three types of synchronization objects:cond,mutex, andrwlock. Each instance table has anEVENT_NAME orNAME column to indicate the instrument associated with each row. Instrument names may have multiple parts and form a hierarchy, as discussed inSection 29.6, “Performance Schema Instrument Naming Conventions”.

Themutex_instances.LOCKED_BY_THREAD_ID andrwlock_instances.WRITE_LOCKED_BY_THREAD_ID columns are extremely important for investigating performance bottlenecks or deadlocks. For examples of how to use them for this purpose, seeSection 29.19, “Using the Performance Schema to Diagnose Problems”