30.4.3.1 The host_summary and x$host_summary Views

These views summarize statement activity, file I/O, and connections, grouped by host.

The host_summary and x$host_summary 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.

• statements

  The total number of statements for the host.

• statement_latency

  The total wait time of timed statements for the host.

• statement_avg_latency

  The average wait time per timed statement for the host.

• table_scans

  The total number of table scans for the host.

• file_ios

  The total number of file I/O events for the host.

• file_io_latency

  The total wait time of timed file I/O events for the host.

• current_connections

  The current number of connections for the host.

• total_connections

  The total number of connections for the host.

• unique_users

  The number of distinct users for the host.

• current_memory

  The current amount of allocated memory for the host.

• total_memory_allocated

  The total amount of allocated memory for the host.