Example Consumer Configurations-opracowanie

Example Consumer Configurations
The consumer settings in the setup_consumers table form a hierarchy from higher levels to lower.
The following discussion describes how consumers work, showing specific configurations and their
effects as consumer settings are enabled progressively from high to low. The consumer values shown
are representative. The general 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 code on your behalf and you will have less information to sift through.
Suppose that the setup_consumers table contains the following hierarchy of values:
global_instrumentation
thread_instrumentation
events_waits_current
events_waits_history
events_waits_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).
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