Performance Schema Miscellaneous Tables •The Performance Schema must be enabled at server startup. This is true by default; it is controlled using the  performance_schema  system variable. •Recommended configuration: •To avoid having some threads ignored: •Leave the  performance_schema_max_thread_instances  system variable set to its default or set it at least as great as the  max_connections  system variable. •Leave the  performance_schema_max_thread_classes  system variable set to its default. •To avoid having some  STATE  column values be empty, leave the performance_schema_max_stage_classes  system variable set to its default. The default for those configuration parameters is  -1 , which causes the Performance Schema to autosize them at server startup. With the parameters set as indicated, the  processlist  table (and thus  SHOW PROCESSLIST ) produce complete process information. The preceding configuration parameters affect the contents of the  processlist  table. For a given configuration, however, the  processlist  contents are unaffected by the performance_schema_show_processlist  setting. The alternative process list implementation does not apply to the  INFORMATION_SCHEMA PROCESSLIST table or the  COM_PROCESS_INFO  command of the MySQL client/server protocol. The  threads  table contains a row for each server thread. Each row contains information about a thread and indicates whether monitoring and historical event logging are enabled for it: 27.12.21.6 The threads Table With that configuration satisfied,  performance_schema_show_processlist  enables or disables the alternative  SHOW PROCESSLIST  implementation. If the minimum configuration is not satisfied, the processlist  table (and thus  SHOW PROCESSLIST ) may not return all data. mysql>  SELECT * FROM performance_schema.threads\G *************************** 1. row *************************** THREAD_ID: 1 NAME: thread/sql/main TYPE: BACKGROUND PROCESSLIST_ID: NULL PROCESSLIST_USER: NULL PROCESSLIST_HOST: NULL PROCESSLIST_DB: NULL PROCESSLIST_COMMAND: NULL PROCESSLIST_TIME: 80284 PROCESSLIST_STATE: NULL PROCESSLIST_INFO: NULL PARENT_THREAD_ID: NULL ROLE: NULL INSTRUMENTED: YES HISTORY: YES CONNECTION_TYPE: NULL THREAD_OS_ID: 489803 RESOURCE_GROUP: SYS_default ... *************************** 4. row *************************** THREAD_ID: 51 NAME: thread/sql/one_connection TYPE: FOREGROUND 5088