host_summary_by_stages and x$host_summary_by_stages Sys Schema Views

These views summarize statement execution stages grouped by host, showing where threads spend the most time during query processing.

Sys Schema views are available from MariaDB 10.6.

Description

The host_summary_by_stages and x$host_summary_by_stages views summarize statement stages, grouped by host. Rows are sorted by host and descending total latency by default. The host_summary_by_stages view is intended to be easier for human reading, while the x$host_summary_by_stages view provides the data in raw form, intended for tools that process the data.

They contain the following columns:

Column	Description
host	Host that the client connected from, or background for background threads (where the HOST column in the underlying Performance Schema table is NULL).
event_name	Stage event name.
total	Total number of occurrences of the file stage event for the host.
total_latency	Total wait time of timed occurrences of the stage event for the host.
avg_latency	Average wait time per timed occurrence of the stage event for the host.

Example

SELECT * FROM sys.host_summary_by_stages\G
*************************** 1. row ***************************
         host: background
   event_name: stage/innodb/buffer pool load
        total: 1
total_latency: 3.75 ms
  avg_latency: 3.75 ms

SELECT * FROM sys.x$host_summary_by_stages\G
*************************** 1. row ***************************
         host: background
   event_name: stage/innodb/buffer pool load
        total: 1
total_latency: 3747098000
  avg_latency: 3747098000

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