MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
These views summarize statement stages, grouped by host. By default, rows are sorted by host and descending total latency.
The host_summary_by_stages and
x$host_summary_by_stages views
have these columns:
host
The host from which the client connected. Rows for which
the HOST 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 host.
total_latency
The total wait time of timed occurrences of the stage event for the host.
avg_latency
The average wait time per timed occurrence of the stage event for the host.