io_global_by_wait_by_latency and x$io_global_by_wait_by_latency Sys Schema Views
MariaDB starting with 10.6
These Sys Schema views were introduced in MariaDB 10.6.
Description
The io_global_by_wait_by_latency and x$io_global_by_wait_by_latency views summarize global I/O consumers, displaying I/O and time waiting for I/O, grouped by event. Rows are sorted by descending total latency by default.
The io_global_by_wait_by_latency view is intended to be easier for human reading, while the x$io_global_by_wait_by_latency view provides the data in raw form, intended for tools that process the data.
They contain the following columns:
| Column | Description |
|---|---|
| event_name | I/O event name. The wait/io/file prefix is stripped. |
| total | Total number of occurrences of the I/O event. |
| total_latency | Total wait time of timed occurrences of the I/O event. |
| min_latency | Minimum single wait time of timed occurrences of the I/O event. |
| avg_latency | Average wait time per timed occurrence of the I/O event. |
| max_latency | Maximum single wait time of timed occurrences of the I/O event. |
| count_read | Total number of read request for the I/O event. |
| total_read | Total number of bytes read for the I/O event. |
| avg_read | Average number of bytes per read for the I/O event. |
| count_write | Total number of write requests for the I/O event. |
| total_written | Number of bytes written for the I/O event. |
| avg_written | Average number of bytes per write for the I/O event. |
| total_requested | Total number of bytes (read and write) for the I/O event. |
Example
SELECT * FROM sys.io_global_by_wait_by_latency\G
*************************** 1. row ***************************
event_name: sql/global_ddl_log
total: 223
total_latency: 288.66 ms
avg_latency: 1.29 ms
max_latency: 26.07 ms
read_latency: 0 ps
write_latency: 2.59 ms
misc_latency: 286.07 ms
count_read: 0
total_read: 0 bytes
avg_read: 0 bytes
count_write: 114
total_written: 220.17 KiB
avg_written: 1.93 KiB
*************************** 2. row ***************************
event_name: innodb/innodb_log_file
total: 95
total_latency: 165.29 ms
avg_latency: 1.74 ms
max_latency: 26.48 ms
read_latency: 61.04 us
write_latency: 1.31 ms
misc_latency: 163.92 ms
count_read: 6
total_read: 66.50 KiB
avg_read: 11.08 KiB
count_write: 43
total_written: 81.00 KiB
avg_written: 1.88 KiB
...
SELECT * FROM sys.x$io_global_by_wait_by_latency\G
*************************** 1. row ***************************
event_name: sql/global_ddl_log
total: 223
total_latency: 288663966666
avg_latency: 1294456930
max_latency: 26072142152
read_latency: 0
write_latency: 2594925264
misc_latency: 286069041402
count_read: 0
total_read: 0
avg_read: 0.0000
count_write: 114
total_written: 225459
avg_written: 1977.7105
*************************** 2. row ***************************
event_name: innodb/innodb_log_file
total: 95
total_latency: 165291020006
avg_latency: 1739905288
max_latency: 26478157582
read_latency: 61040974
write_latency: 1310187820
misc_latency: 163919791212
count_read: 6
total_read: 68096
avg_read: 11349.3333
count_write: 43
total_written: 82944
avg_written: 1928.9302
...
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