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:

Column
Description

Column

Description

THREAD_ID

Thread associated with the event. Together with EVENT_ID uniquely identifies the row.

EVENT_ID

Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.

END_EVENT_ID

NULL when the event starts, set to the thread's current event number at the end of the event.

EVENT_NAME

Event instrument name and a NAME from the setup_instruments table

SOURCE

Name and line number of the source file containing the instrumented code that produced the event.

TIMER_START

Value in picoseconds when the event timing started or NULL if timing is not collected.

TIMER_END

Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.

TIMER_WAIT

Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.

SPINS

Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.

OBJECT_SCHEMA

Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.

OBJECT_NAME

File 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.

INDEX NAME

Name of the index, PRIMARY for the primary key, or NULL for no index used.

OBJECT_TYPE

FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.

OBJECT_INSTANCE_BEGIN

Address in memory of the object.

NESTING_EVENT_ID

EVENT_ID of event within which this event nests.

NESTING_EVENT_TYPE

Nesting event type. Either statement, stage or wait.

OPERATION

Operation type, for example read, write or lock

NUMBER_OF_BYTES

Number of bytes that the operation read or wrote, or NULL for table I/O waits.

FLAGS

Reserved 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.

This page is licensed: CC BY-SA / Gnu FDL

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