26.4.3.44 The user_summary_by_stages and x$user_summary_by_stages Views

These views summarize stages, grouped by user. By default, rows are sorted by user and descending total stage latency.

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.