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MySQL 5.7 Reference Manual  /  MySQL Performance Schema  /  Performance Schema Build Configuration

24.2 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:

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

For more information, see the descriptions of the DISABLE_PSI_XXX CMake options in Section 2.9.4, “MySQL 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 may not have all the current tables), run mysql_upgrade after starting the server to ensure that the performance_schema database exists with all current tables. Then restart the server. One indication that you need to do this 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 verify whether a server was built with Performance Schema support, check its help output. If the Performance Schema is available, the output will mention several variables with names that begin with performance_schema:

shell> 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 PERFORMANCE_SCHEMA storage engine in the output from 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 PERFORMANCE_SCHEMA will appear in the output from SHOW ENGINES. You might see performance_schema listed in the output from SHOW DATABASES, but it will have no tables and you will not be able to use it.

A line for PERFORMANCE_SCHEMA in the 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.


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