io_by_thread_by_latency and x$io_by_thread_by_latency Sys Schema Views

These views rank threads by I/O latency, making it easier to identify specific threads that are consuming the most disk resources.

Sys Schema views are available from MariaDB 10.6.

Description

The io_by_thread_by_latency and x$io_by_thread_by_latency view summarize I/O consumers to display time waiting for I/O, grouped by thread. Rows are sorted by descending total I/O latency by default.

The io_by_thread_by_latency view is intended to be easier for human reading, while the x$io_by_thread_by_latency view provides the data in raw form, intended for tools that process the data.

They contain the following columns:

Column	Description
user	The account associated with a foreground thread, or the background thread name
total	Total number of I/O events allocated for the thread.
total_latency	Total wait time of timed I/O events for the thread.
min_latency	Minimum single wait time of timed I/O events for the thread.
avg_latency	Average wait time per timed I/O event for the thread.
min_latency	Maximum single wait time of timed I/O events for the thread.
thread_id	Thread id.
processlist_id	Processlist id for foreground threads, or NULL for background threads.

Example

SELECT * FROM sys.io_by_thread_by_latency\G
*************************** 1. row ***************************
          user: main
         total: 378
 total_latency: 40.11 ms
   min_latency: 570.21 ns
   avg_latency: 206.02 us
   max_latency: 4.33 ms
     thread_id: 1
processlist_id: NULL
*************************** 2. row ***************************
          user: msandbox@localhost
         total: 521
 total_latency: 10.28 ms
   min_latency: 775.04 ns
   avg_latency: 21.79 us
   max_latency: 977.79 us
     thread_id: 89
processlist_id: 7

...

SELECT * FROM sys.x$io_by_thread_by_latency\G
*************************** 1. row ***************************
          user: main
         total: 378
 total_latency: 40106340880
   min_latency: 570208
   avg_latency: 206016046.6000
   max_latency: 4327780456
     thread_id: 1
processlist_id: NULL
*************************** 2. row ***************************
          user: msandbox@localhost
         total: 498
 total_latency: 9637694714
   min_latency: 775040
   avg_latency: 21364289.0000
   max_latency: 977787350
     thread_id: 89
processlist_id: 7

...

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