25.2 Performance Schema Build Configuration

The Performance Schema is mandatory and always compiled in. It is possible to exclude certain parts of the Performance Schema instrumentation. For example, to exclude stage and statement instrumentation, do this:

 $> cmake . \
         -DDISABLE_PSI_STAGE=1 \
         -DDISABLE_PSI_STATEMENT=1

For more information, see the descriptions of the 'DISABLE_PSI_XXX' 'CMake' options in *note source-configuration-options::.

If you install MySQL over a previous installation that was configured without the Performance Schema (or with an older version of the Performance Schema that has missing or out-of-date tables). One indication of this issue is the presence of messages such as the following in the error log:

 [ERROR] Native table 'performance_schema'.'events_waits_history'
 has the wrong structure
 [ERROR] Native table 'performance_schema'.'events_waits_history_long'
 has the wrong structure
 ...

To correct that problem, perform the MySQL upgrade procedure. See *note upgrading::.

To verify whether a server was built with Performance Schema support, check its help output. If the Performance Schema is available, the output mentions several variables with names that begin with 'performance_schema':

 $> mysqld --verbose --help
 ...
   --performance_schema
                       Enable the performance schema.
   --performance_schema_events_waits_history_long_size=#
                       Number of rows in events_waits_history_long.
 ...

You can also connect to the server and look for a line that names the note 'PERFORMANCE_SCHEMA': performance-schema. storage engine in the output from note 'SHOW ENGINES': show-engines.:

 mysql> SHOW ENGINES\G
 ...
       Engine: PERFORMANCE_SCHEMA
      Support: YES
      Comment: Performance Schema
 Transactions: NO
           XA: NO
   Savepoints: NO
 ...

If the Performance Schema was not configured into the server at build time, no row for note 'PERFORMANCE_SCHEMA': performance-schema. appears in the output from note 'SHOW ENGINES': show-engines. You might see 'performance_schema' listed in the output from *note 'SHOW DATABASES': show-databases, but it has no tables and cannot be used.

A line for note 'PERFORMANCE_SCHEMA': performance-schema. in the note 'SHOW ENGINES': show-engines. output means that the Performance Schema is available, not that it is enabled. To enable it, you must do so at server startup, as described in the next section.

 File: manual.info.tmp, Node: performance-schema-startup-configuration, Next: performance-schema-runtime-configuration, Prev: performance-schema-build-configuration, Up: performance-schema