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Example Consumer Configurations

The consumer settings in the setup_consumers table form a hierarchy from higher levels to lo\M3r.

Thefollowing discussion describes howconsumers work, showing specific configurations and their

effects as consumer settings are enabled progressively from high to Iow. The consumer values shown

are representative. The generał principles described here apply to other consumer

values that may be

available.

The configuration descriptions occur in order of increasing functionality and overhead. If you do not

need the information provided by enabling lower-level settings, disable them and the Performance

Schema will execute less codę on your behalf and you will have less information to siftthrough.

Suppose that the setup_consumers table contains the following hierarchy of values:

global_instrumentation

thread_instrumentation

event3_waits_current

events_wait3_history

events_wait3_history_long

If a given consumer setting is NO, the Performance Schema disables the instrumentation associated

with the consumer and ignores all lower-level settings. If a given setting is YES, the Performance

Schema enables the instrumentation associated with it and checks the settings at the next lowest level.

Each configuration description indicates which setup elements the Performance Schema checks and

which output tables it maintains (that is, for which tables it collects information).