Performance Schema Setup Tables • setup_consumers : The destinations to which event information can be sent and stored • setup_instruments : The classes of instrumented objects for which events can be collected • setup_objects : Which objects should be monitored • setup_threads : Instrumented thread names and attributes 27.12.2.1 The setup_actors Table The  setup_actors  table contains information that determines whether to enable monitoring and historical event logging for new foreground server threads (threads associated with client connections). This table has a maximum size of 100 rows by default. To change the table size, modify the performance_schema_setup_actors_size  system variable at server startup. For each new foreground thread, the Performance Schema matches the user and host for the thread against the rows of the  setup_actors  table. If a row from that table matches, its  ENABLED  and  HISTORY column values are used to set the  INSTRUMENTED  and  HISTORY  columns, respectively, of the  threads table row for the thread. This enables instrumenting and historical event logging to be applied selectively per host, user, or account (user and host combination). If there is no match, the  INSTRUMENTED  and HISTORY  columns for the thread are set to  NO . For background threads, there is no associated user.  INSTRUMENTED  and  HISTORY  are  YES  by default and  setup_actors  is not consulted. The initial contents of the  setup_actors  table match any user and host combination, so monitoring and historical event collection are enabled by default for all foreground threads: For information about how to use the  setup_actors  table to affect event monitoring, see Section 27.4.6, “Pre-Filtering by Thread” . mysql>  SELECT * FROM performance_schema.setup_actors; +------+------+------+---------+---------+ | HOST | USER | ROLE | ENABLED | HISTORY | +------+------+------+---------+---------+ | % | % | % | YES | YES | +------+------+------+---------+---------+ Modifications to the  setup_actors  table affect only foreground threads created subsequent to the modification, not existing threads. To affect existing threads, modify the  INSTRUMENTED  and  HISTORY columns of  threads  table rows. The  setup_actors  table has these columns: The host name. This should be a literal name, or  ’%’  to mean “any host.” The user name. This should be a literal name, or  ’%’  to mean “any user.” Unused. Whether to enable instrumentation for foreground threads matched by the row. The value is  YES  or  NO . 4945 • HOST • USER • ROLE • ENABLED