MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
These views summarize file I/O, grouped by user. By default, rows are sorted by descending total file I/O latency.
Theuser_summary_by_file_io
andx$user_summary_by_file_io
views have these columns:
user
The client user name. Rows for which the
USER
column in the underlying Performance Schema table isNULL
are assumed to be for background threads and are reported with a host name ofbackground
.ios
The total number of file I/O events for the user.
io_latency
The total wait time of timed file I/O events for the user.