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MySQL 5.6 Reference Manual
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22.9.5.1 The events_stages_current Table

The events_stages_current table contains current stage events, one row per thread showing the current status of the thread's most recent monitored stage event.

The events_stages_current table can be truncated with TRUNCATE TABLE.

Of the tables that contain stage event rows, events_stages_current is the most fundamental. Other tables that contain stage event rows are logically derived from the current events. For example, the events_stages_history and events_stages_history_long tables are collections of the most recent stage events, up to a fixed number of rows.

For information about configuration of stage event collection, see Section 22.9.5, “Performance Schema Stage Event Tables”.

The events_stages_current table has these columns:

  • THREAD_ID, EVENT_ID

    The thread associated with the event and the thread current event number when the event starts. The THREAD_ID and EVENT_ID values taken together form a primary key that uniquely identifies the row. No two rows will have the same pair of values.

  • END_EVENT_ID

    This column is set to NULL when the event starts and updated to the thread current event number when the event ends. This column was added in MySQL 5.6.4.

  • EVENT_NAME

    The name of the instrument that produced the event. This is a NAME value from the setup_instruments table. Instrument names may have multiple parts and form a hierarchy, as discussed in Section 22.4, “Performance Schema Instrument Naming Conventions”.

  • SOURCE

    The name of the source file containing the instrumented code that produced the event and the line number in the file at which the instrumentation occurs. This enables you to check the source to determine exactly what code is involved.

  • TIMER_START, TIMER_END, TIMER_WAIT

    Timing information for the event. The unit for these values is picoseconds (trillionths of a second). The TIMER_START and TIMER_END values indicate when event timing started and ended. TIMER_WAIT is the event elapsed time (duration).

    If an event has not finished, TIMER_END and TIMER_WAIT are NULL before MySQL 5.6.26. As of 5.6.26, TIMER_END is the current timer value and TIMER_WAIT is the time elapsed so far (TIMER_ENDTIMER_START).

    If an event is produced from an instrument that has TIMED = NO, timing information is not collected, and TIMER_START, TIMER_END, and TIMER_WAIT are all NULL.

    For discussion of picoseconds as the unit for event times and factors that affect time values, see Section 22.2.3.1, “Performance Schema Event Timing”.

  • NESTING_EVENT_ID

    The EVENT_ID value of the event within which this event is nested. The nesting event for a stage event is usually a statement event.

  • NESTING_EVENT_TYPE

    The nesting event type. The value is STATEMENT, STAGE, or WAIT.

The events_stages_current table was added in MySQL 5.6.3.


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