Determining What Is Instrumented-opracowanie

Determining What Is Instrumented
It is always possible to determine what instruments the Performance Schema includes by checking
the setup_instruments table. For example, to see what file-related events are instrumented for the
InnoDB storage engine, use this query:
mysql SELECT * FROM setup_instruments WHERE NAME LIKE 'wait/io/file/innodb/%';
+--------------------------------------+---------+-------+
| NAME | ENABLED | TIMED |
+--------------------------------------+---------+-------+
| wait/io/file/innodb/innodb_data_file | YES | YES |
| wait/io/file/innodb/innodb_log_file | YES | YES |
| wait/io/file/innodb/innodb_temp_file | YES | YES |
+--------------------------------------+---------+-------+
An exhaustive description of precisely what is instrumented is not given in this documentation, for
several reasons:
• What is instrumented is the server code. Changes to this code occur often, which also affects the set
of instruments.
• It is not practical to list all the instruments because there are hundreds of them.
• As described earlier, it is possible to find out by querying the setup_instruments table. This
information is always up to date for your version of MySQL, also includes instrumentation for
instrumented plugins you might have installed that are not part of the core server, and can be used
by automated tools.
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