Documentation Home
MySQL 9.4 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 41.2Mb
PDF (A4) - 41.3Mb
Man Pages (TGZ) - 262.8Kb
Man Pages (Zip) - 368.8Kb
Info (Gzip) - 4.1Mb
Info (Zip) - 4.1Mb


29.12.2.5 The setup_threads Table

Thesetup_threads table lists instrumented thread classes. It exposes thread class names and attributes:

mysql> SELECT * FROM performance_schema.setup_threads\G*************************** 1. row ***************************         NAME: thread/performance_schema/setup      ENABLED: YES      HISTORY: YES   PROPERTIES: singleton   VOLATILITY: 0DOCUMENTATION: NULL...*************************** 4. row ***************************         NAME: thread/sql/main      ENABLED: YES      HISTORY: YES   PROPERTIES: singleton   VOLATILITY: 0DOCUMENTATION: NULL*************************** 5. row ***************************         NAME: thread/sql/one_connection      ENABLED: YES      HISTORY: YES   PROPERTIES: user   VOLATILITY: 0DOCUMENTATION: NULL...*************************** 10. row ***************************         NAME: thread/sql/event_scheduler      ENABLED: YES      HISTORY: YES   PROPERTIES: singleton   VOLATILITY: 0DOCUMENTATION: NULL

Thesetup_threads table has these columns:

  • NAME

    The instrument name. Thread instruments begin withthread (for example,thread/sql/parser_service orthread/performance_schema/setup).

  • ENABLED

    Whether the instrument is enabled. The value isYES orNO. This column can be modified, although settingENABLED has no effect for threads that are already running.

    For background threads, setting theENABLED value controls whetherINSTRUMENTED is set toYES orNO for threads that are subsequently created for this instrument and listed in thethreads table. For foreground threads, this column has no effect; thesetup_actors table takes precedence.

  • HISTORY

    Whether to log historical events for the instrument. The value isYES orNO. This column can be modified, although settingHISTORY has no effect for threads that are already running.

    For background threads, setting theHISTORY value controls whetherHISTORY is set toYES orNO for threads that are subsequently created for this instrument and listed in thethreads table. For foreground threads, this column has no effect; thesetup_actors table takes precedence.

  • PROPERTIES

    The instrument properties. This column uses theSET data type, so multiple flags from the following list can be set per instrument:

    • singleton: The instrument has a single instance. For example, there is only one thread for thethread/sql/main instrument.

    • user: The instrument is directly related to user workload (as opposed to system workload). For example, threads such asthread/sql/one_connection executing a user session have theuser property to differentiate them from system threads.

  • VOLATILITY

    The instrument volatility. This column has the same meaning as in thesetup_instruments table. SeeSection 29.12.2.3, “The setup_instruments Table”.

  • DOCUMENTATION

    A string describing the instrument purpose. The value isNULL if no description is available.

Thesetup_threads table has these indexes:

  • Primary key on (NAME)

TRUNCATE TABLE is not permitted for thesetup_threads table.