Performance Schema Startup Configuration Here,  consumer_name  is a consumer name such as  events_waits_history , and  value  is one of these values: For example, to enable the  events_waits_history  consumer, use this option: The permitted consumer names can be found by examining the  setup_consumers  table. Patterns are not permitted. Consumer names in the  setup_consumers  table use underscores, but for consumers set at startup, dashes and underscores within the name are equivalent. The Performance Schema includes several system variables that provide configuration information: The  performance_schema  variable is  ON  or  OFF  to indicate whether the Performance Schema is enabled or disabled. The other variables indicate table sizes (number of rows) or memory allocation values. With the Performance Schema enabled, the number of Performance Schema instances affects the server memory footprint, perhaps to a large extent. The Performance Schema autoscales many parameters to use memory only as required; see Section 27.17, “The Performance Schema Memory-Allocation Model” . To change the value of Performance Schema system variables, set them at server startup. For example, put the following lines in a  my.cnf  file to change the sizes of the history tables for wait events: The Performance Schema automatically sizes the values of several of its parameters at server startup if they are not set explicitly. For example, it sizes the parameters that control the sizes of the events waits tables this way. The Performance Schema allocates memory incrementally, scaling its memory use to actual server load, instead of allocating all the memory it needs during server startup. Consequently, 4903 Note --performance-schema-consumer- consumer_name = value mysql>  SHOW VARIABLES LIKE ’perf%’; [mysqld] performance_schema performance_schema_events_waits_history_size=20 performance_schema_events_waits_history_long_size=15000 • OFF ,  FALSE , or  0 : Do not collect events for the consumer • ON ,  TRUE , or  1 : Collect events for the consumer --performance-schema-consumer-events-waits-history=ON +--------------------------------------------------------+---------+ | Variable_name | Value | +--------------------------------------------------------+---------+ | performance_schema | ON | | performance_schema_accounts_size | 100 | | performance_schema_digests_size | 200 | | performance_schema_events_stages_history_long_size | 10000 | | performance_schema_events_stages_history_size | 10 | | performance_schema_events_statements_history_long_size | 10000 | | performance_schema_events_statements_history_size | 10 | | performance_schema_events_waits_history_long_size | 10000 | | performance_schema_events_waits_history_size | 10 | | performance_schema_hosts_size | 100 | | performance_schema_max_cond_classes | 80 | | performance_schema_max_cond_instances | 1000 | ...