MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
These views summarize stages, grouped by user. By default, rows are sorted by user and descending total stage latency.
The user_summary_by_stages and
x$user_summary_by_stages views
have these columns:
user
The client user name. Rows for which the
USER column in the underlying
Performance Schema table is NULL are
assumed to be for background threads and are reported with
a host name of background.
event_name
The stage event name.
total
The total number of occurrences of the stage event for the user.
total_latency
The total wait time of timed occurrences of the stage event for the user.
avg_latency
The average wait time per timed occurrence of the stage event for the user.