MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
These views summarize statement activity, file I/O, and connections, grouped by user. By default, rows are sorted by descending total latency.
The user_summary and
x$user_summary 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.
statements
The total number of statements for the user.
statement_latency
The total wait time of timed statements for the user.
statement_avg_latency
The average wait time per timed statement for the user.
table_scans
The total number of table scans for the user.
file_ios
The total number of file I/O events for the user.
file_io_latency
The total wait time of timed file I/O events for the user.
current_connections
The current number of connections for the user.
total_connections
The total number of connections for the user.
unique_hosts
The number of distinct hosts from which connections for the user have originated.
current_memory
The current amount of allocated memory for the user.
total_memory_allocated
The total amount of allocated memory for the user.