MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
These views summarize wait class total latencies, grouped by event class. By default, rows are sorted by descending total latency. Idle events are ignored.
An event class is determined by stripping from the event name
everything after the first three components. For example, the
class for wait/io/file/sql/slow_log is
wait/io/file.
The
wait_classes_global_by_latency
and
x$wait_classes_global_by_latency
views have these columns:
event_class
The event class.
total
The total number of occurrences of events in the class.
total_latency
The total wait time of timed occurrences of events in the class.
min_latency
The minimum single wait time of timed occurrences of events in the class.
avg_latency
The average wait time per timed occurrence of events in the class.
max_latency
The maximum single wait time of timed occurrences of events in the class.