MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
These views summarize global I/O consumers to display amount of I/O and time waiting for I/O, grouped by event. By default, rows are sorted by descending total latency.
The io_global_by_wait_by_latency
and
x$io_global_by_wait_by_latency
views have these columns:
event_name
The I/O event name, with the
wait/io/file/ prefix stripped.
total
The total number of occurrences of the I/O event.
total_latency
The total wait time of timed occurrences of the I/O event.
avg_latency
The average wait time per timed occurrence of the I/O event.
max_latency
The maximum single wait time of timed occurrences of the I/O event.
read_latency
The total wait time of timed read occurrences of the I/O event.
write_latency
The total wait time of timed write occurrences of the I/O event.
misc_latency
The total wait time of timed other occurrences of the I/O event.
count_read
The number of read requests for the I/O event.
total_read
The number of bytes read for the I/O event.
avg_read
The average number of bytes per read for the I/O event.
count_write
The number of write requests for the I/O event.
total_written
The number of bytes written for the I/O event.
avg_written
The average number of bytes per write for the I/O event.