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UPDATE performance_schema.setup_instruments SET enabled = 'NO', timed = 'YES';
UPDATE performance_schema.setup_instruments SET enabled = 'YES'
WHERE name LIKE 'wait/synch/mutex/%'
OR name LIKE 'wait/synch/rwlock/%';
truncate table performance_schema.events_statements_summary_by_digest;
flush status;
select NAME from performance_schema.mutex_instances
where NAME = 'wait/synch/mutex/sql/LOCK_open';
NAME
wait/synch/mutex/sql/LOCK_open
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (id INT PRIMARY KEY, b CHAR(100) DEFAULT 'initial value')
ENGINE=MyISAM;
INSERT INTO t1 (id) VALUES (1), (2), (3), (4), (5), (6), (7), (8);
TRUNCATE TABLE performance_schema.events_waits_history_long;
TRUNCATE TABLE performance_schema.events_waits_history;
TRUNCATE TABLE performance_schema.events_waits_current;
SELECT * FROM t1 WHERE id = 1;
id b
1 initial value
CREATE TABLE t2 SELECT * FROM performance_schema.events_waits_history_long
WHERE (EVENT_NAME = 'wait/synch/mutex/sql/LOCK_table_cache');
SET @before_count = (SELECT SUM(TIMER_WAIT) FROM t2);
TRUNCATE TABLE performance_schema.events_waits_history_long;
SELECT * FROM t1;
id b
1 initial value
2 initial value
3 initial value
4 initial value
5 initial value
6 initial value
7 initial value
8 initial value
INSERT INTO t2 SELECT * FROM performance_schema.events_waits_history_long
WHERE (EVENT_NAME = 'wait/synch/mutex/sql/LOCK_table_cache');
SET @after_count = (SELECT SUM(TIMER_WAIT) FROM t2);
SELECT IF(@after_count < @before_count, 'Failue', 'Success') test_fm1_timed;
test_fm1_timed
Success
DROP TABLE t2;
UPDATE performance_schema.setup_instruments SET enabled = 'NO'
WHERE NAME = 'wait/synch/mutex/sql/LOCK_table_cache';
TRUNCATE TABLE performance_schema.events_waits_history_long;
TRUNCATE TABLE performance_schema.events_waits_history;
TRUNCATE TABLE performance_schema.events_waits_current;
SELECT * FROM t1 WHERE id = 1;
id b
1 initial value
SET @before_count = (SELECT SUM(TIMER_WAIT)
FROM performance_schema.events_waits_history_long
WHERE (EVENT_NAME = 'wait/synch/mutex/sql/LOCK_table_cache'));
SELECT * FROM t1;
id b
1 initial value
2 initial value
3 initial value
4 initial value
5 initial value
6 initial value
7 initial value
8 initial value
SET @after_count = (SELECT SUM(TIMER_WAIT)
FROM performance_schema.events_waits_history_long
WHERE (EVENT_NAME = 'wait/synch/mutex/sql/LOCK_table_cache'));
SELECT IF((COALESCE(@after_count, 0) - COALESCE(@before_count, 0)) = 0, 'Success', 'Failure') test_fm2_timed;
test_fm2_timed
Success
UPDATE performance_schema.setup_instruments SET enabled = 'YES';
DROP TABLE t1;
UPDATE performance_schema.setup_instruments SET enabled = 'YES', timed = 'YES';
show global status like "performance_schema%_lost";
Variable_name Value
Performance_schema_accounts_lost 0
Performance_schema_cond_classes_lost 0
Performance_schema_cond_instances_lost 0
Performance_schema_digest_lost 0
Performance_schema_file_classes_lost 0
Performance_schema_file_handles_lost 0
Performance_schema_file_instances_lost 0
Performance_schema_hosts_lost 0
Performance_schema_index_stat_lost 0
Performance_schema_locker_lost 0
Performance_schema_memory_classes_lost 0
Performance_schema_metadata_lock_lost 0
Performance_schema_mutex_classes_lost 0
Performance_schema_mutex_instances_lost 0
Performance_schema_nested_statement_lost 0
Performance_schema_prepared_statements_lost 0
Performance_schema_program_lost 0
Performance_schema_rwlock_classes_lost 0
Performance_schema_rwlock_instances_lost 0
Performance_schema_session_connect_attrs_lost 0
Performance_schema_socket_classes_lost 0
Performance_schema_socket_instances_lost 0
Performance_schema_stage_classes_lost 0
Performance_schema_statement_classes_lost 0
Performance_schema_table_handles_lost 0
Performance_schema_table_instances_lost 0
Performance_schema_table_lock_stat_lost 0
Performance_schema_thread_classes_lost 0
Performance_schema_thread_instances_lost 0
Performance_schema_users_lost 0
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