Performance Schema Miscellaneous Tables The  performance_timers  table shows which event timers are available: mysql>  SELECT * FROM performance_schema.performance_timers; +-------------+-----------------+------------------+----------------+ | TIMER_NAME | TIMER_FREQUENCY | TIMER_RESOLUTION | TIMER_OVERHEAD | +-------------+-----------------+------------------+----------------+ | CYCLE | 2389029850 | 1 | 72 | | NANOSECOND | 1000000000 | 1 | 112 | | MICROSECOND | 1000000 | 1 | 136 | | MILLISECOND | 1036 | 1 | 168 | +-------------+-----------------+------------------+----------------+ If the values associated with a given timer name are  NULL , that timer is not supported on your platform. For an explanation of how event timing occurs, see Section 27.4.1, “Performance Schema Event Timing” . The  performance_timers  table has these columns: The timer name. The number of timer units per second. For a cycle timer, the frequency is generally related to the CPU speed. For example, on a system with a 2.4GHz processor, the  CYCLE  may be close to 2400000000. Indicates the number of timer units by which timer values increase. If a timer has a resolution of 10, its value increases by 10 each time. The minimal number of cycles of overhead to obtain one timing with the given timer. The Performance Schema determines this value by invoking the timer 20 times during initialization and picking the smallest value. The total overhead really is twice this amount because the instrumentation invokes the timer at the start and end of each event. The timer code is called only for timed events, so this overhead does not apply for nontimed events. The  performance_timers  table has no indexes. TRUNCATE TABLE  is not permitted for the  performance_timers  table. • TIMER_NAME • TIMER_FREQUENCY • TIMER_RESOLUTION • TIMER_OVERHEAD 27.12.21.5 The processlist Table The MySQL process list indicates the operations currently being performed by the set of threads executing within the server. The  processlist  table is one source of process information. For a comparison of this table with other sources, see Sources of Process Information. The  processlist  table can be queried directly. If you have the  PROCESS  privilege, you can see all threads, even those belonging to other users. Otherwise (without the  PROCESS  privilege), nonanonymous users have access to information about their own threads but not threads for other users, and anonymous users have no access to thread information. If the  performance_schema_show_processlist  system variable is enabled, the  processlist  table also serves as the basis for an alternative implementation underlying the  SHOW PROCESSLIST  statement. For details, see later in this section. Note 5085