Spec-Zone .ru
спецификации, руководства, описания, API
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Spec-Zone .ru
спецификации, руководства, описания, API
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The events_statements_current table contains current statement events, one row per
thread showing the current status of the thread's most recent monitored statement event.
The events_statements_current table can be truncated with TRUNCATE TABLE.
Of the tables that contain statement event rows, events_statements_current is the most fundamental. Other tables that contain
statement event rows are logically derived from the current events. For example, the events_statements_history and events_statements_history_long tables are collections of the most recent
statement events, up to a fixed number of rows.
The events_statements_current table has these columns:
THREAD_ID
The thread associated with the event. 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.
EVENT_ID
The thread current event number when the event starts.
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.
EVENT_NAME
The name of the instrument from which the event was collected. This is a setup_instruments.NAME
value. Instrument names have multiple parts and form a hierarchy, as discussed in Section
20.4, "Performance Schema Instrument Naming Conventions".
For SQL statements, the EVENT_NAME value initially is statement/com/Query until the statement is parsed, then changes to a more
appropriate value, as described in Section
20.9.5, "Performance Schema Statement Event Tables".
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.
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 20.2.3.1, "Performance Schema Event Timing".
LOCK_TIME
The time spent waiting for table locks. This value is computed in microseconds but normalized to picoseconds for easier comparison with other Performance Schema timers.
SQL_TEXT
The text of the SQL statement. For a command not associated with a SQL statement, the value is NULL.
DIGEST
The statement digest MD5 value as a string of 32 hexadecimal characters, or NULL
if the statement_digest consumer is no.
For more information about statement digesting, see Section
20.7, "Performance Schema Statement Digests".
DIGEST_TEXT
The normalized statement digest text, or NULL if the statement_digest consumer is no. For more
information about statement digesting, see Section
20.7, "Performance Schema Statement Digests".
CURRENT_SCHEMA
The default database for the statement, NULL if there is none.
OBJECT_SCHEMA, OBJECT_NAME,
OBJECT_TYPE
Reserved. Currently NULL.
OBJECT_INSTANCE_BEGIN
This column identifies the statement. The value is the address of an object in memory.
MYSQL_ERRNO
The statement error number, from the statement diagnostics area.
RETURNED_SQLSTATE
The statement SQLSTATE value, from the statement diagnostics area.
MESSAGE_TEXT
The statement error message, from the statement diagnostics area.
ERRORS
Whether an error occurred for the statement. The value is 0 if the SQLSTATE value begins with 00 (completion) or 01 (warning). The value
is 1 is the SQLSTATE value is anything else.
WARNINGS
The number of warnings, from the statement diagnostics area.
ROWS_AFFECTED
The number of rows affected by the statement. For a description of the meaning of "affected," see Section
21.8.7.1, "mysql_affected_rows()".
ROWS_SENT
The number of rows returned by the statement.
ROWS_EXAMINED
The number of rows read from storage engines during statement execution.
CREATED_TMP_DISK_TABLES
Like the Created_tmp_disk_tables status variable, but specific to the
statement.
CREATED_TMP_TABLES
Like the Created_tmp_tables status variable, but specific to the statement.
SELECT_FULL_JOIN
Like the Select_full_join status variable, but specific to the statement.
SELECT_FULL_RANGE_JOIN
Like the Select_full_range_join status variable, but specific to the
statement.
SELECT_RANGE
Like the Select_range status variable, but specific to the statement.
SELECT_RANGE_CHECK
Like the Select_range_check status variable, but specific to the statement.
SELECT_SCAN
Like the Select_scan status variable, but specific to the statement.
SORT_MERGE_PASSES
Like the Sort_merge_passes status variable, but specific to the statement.
SORT_RANGE
Like the Sort_range
status variable, but specific to the statement.
SORT_ROWS
Like the Sort_rows
status variable, but specific to the statement.
SORT_SCAN
Like the Sort_scan
status variable, but specific to the statement.
NO_INDEX_USED
1 if the statement performed a table scan without using an index, 0 otherwise.
NO_GOOD_INDEX_USED
1 if the server found no good index to use for the statement, 0 otherwise. For additional
information, see the description of the Extra column from EXPLAIN output for the Range checked for each
record value in Section 8.8.2, "EXPLAIN Output Format".
NESTING_EVENT_ID, NESTING_EVENT_TYPE
Reserved. Currently NULL.