Performance Schema events_waits_current Table

The events_waits_current table contains the status of a thread's most recently monitored wait event, listing one event per thread.

The table contains the following columns:

ColumnDescription
THREAD_IDThread associated with the event. Together with EVENT_ID uniquely identifies the row.
EVENT_IDThread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
END_EVENT_IDNULL when the event starts, set to the thread's current event number at the end of the event.
EVENT_NAMEEvent instrument name and a NAME from the setup_instruments table
SOURCEName and line number of the source file containing the instrumented code that produced the event.
TIMER_STARTValue in picoseconds when the event timing started or NULL if timing is not collected.
TIMER_ENDValue in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
TIMER_WAITValue in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
SPINSNumber of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.
OBJECT_SCHEMAName of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.
OBJECT_NAMEFile name for file I/O objects, table name for table I/O objects, the socket's IP:PORT value for a socket object or NULL for a synchronization object.
OBJECT_TYPEFILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.
OBJECT_INSTANCE_BEGINAddress in memory of the object.
INDEX NAMEName of the index, PRIMARY for the primary key, or NULL for no index used.
NESTING_EVENT_IDEVENT_ID of event within which this event nests.
NESTING_EVENT_TYPENesting event type. Either statement, stage or wait.
OPERATIONOperation type, for example read, write or lock
NUMBER_OF_BYTESNumber of bytes that the operation read or wrote, or NULL for table I/O waits.
FLAGSReserved for use in the future.

It is possible to empty this table with a TRUNCATE TABLE statement.

The related tables, events_waits_history and events_waits_history_long derive their values from the current events.

Comments

Comments loading...
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.