show databases;
Database
information_schema
mtr
mysql
performance_schema
test
select count(*) from performance_schema.performance_timers;
count(*)
5
select count(*) from performance_schema.setup_consumers;
count(*)
8
select count(*) > 0 from performance_schema.setup_instruments;
count(*) > 0
1
select count(*) from performance_schema.setup_timers;
count(*)
1
select * from performance_schema.cond_instances;
select * from performance_schema.events_waits_current;
select * from performance_schema.events_waits_history;
select * from performance_schema.events_waits_history_long;
select * from performance_schema.events_waits_summary_by_instance;
select * from performance_schema.events_waits_summary_by_thread_by_event_name;
select * from performance_schema.events_waits_summary_global_by_event_name;
select * from performance_schema.file_instances;
select * from performance_schema.file_summary_by_event_name;
select * from performance_schema.file_summary_by_instance;
select * from performance_schema.mutex_instances;
select * from performance_schema.performance_timers;
select * from performance_schema.rwlock_instances;
select * from performance_schema.setup_consumers;
select * from performance_schema.setup_instruments;
select * from performance_schema.setup_timers;
select * from performance_schema.threads;
show variables like "performance_schema%";
Variable_name	Value
performance_schema	ON
performance_schema_events_waits_history_long_size	10000
performance_schema_events_waits_history_size	0
performance_schema_max_cond_classes	80
performance_schema_max_cond_instances	1000
performance_schema_max_file_classes	50
performance_schema_max_file_handles	32768
performance_schema_max_file_instances	10000
performance_schema_max_mutex_classes	200
performance_schema_max_mutex_instances	10000
performance_schema_max_rwlock_classes	30
performance_schema_max_rwlock_instances	10000
performance_schema_max_table_handles	1000
performance_schema_max_table_instances	500
performance_schema_max_thread_classes	50
performance_schema_max_thread_instances	1000
show engine PERFORMANCE_SCHEMA status;
show status like "performance_schema%";
show variables like "performance_schema_events_waits_history_size";
Variable_name	Value
performance_schema_events_waits_history_size	0
select count(*) from performance_schema.events_waits_history;
count(*)
0
truncate table performance_schema.events_waits_history;