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(*) 12 select count(*) > 3 from performance_schema.setup_instruments; count(*) > 3 1 select count(*) from performance_schema.setup_timers; count(*) 4 show engine PERFORMANCE_SCHEMA status; show status like "performance_schema%"; show variables like "performance_schema_max_statement_classes"; Variable_name Value performance_schema_max_statement_classes 0 select count(*) from performance_schema.setup_instruments where name like "statement/%"; count(*) 0 select variable_value > 0 from information_schema.global_status where variable_name like 'PERFORMANCE_SCHEMA_STATEMENT_CLASSES_LOST'; variable_value > 0 1 select count(*) from performance_schema.events_statements_current; count(*) 0 select count(*) from performance_schema.events_statements_history; count(*) 0 select count(*) from performance_schema.events_statements_history_long; count(*) 0 select count(*) from performance_schema.events_statements_summary_by_thread_by_event_name; count(*) 0 select count(*) from performance_schema.events_statements_summary_global_by_event_name; count(*) 0