Performance Schema System Variables • performance_schema_setup_objects_size • performance_schema_show_processlist •The alternative  SHOW PROCESSLIST  implementation is based on the Performance Schema processlist  table. This implementation queries active thread data from the Performance Schema rather than the thread manager and does not require a mutex. •The default implementation iterates across active threads from within the thread manager while holding a global mutex. This has negative performance consequences, particularly on busy systems. • performance_schema_users_size 5118 To enable the alternative implementation, enable the  performance_schema_show_processlist system variable. To ensure that the default and alternative implementations yield the same information, certain configuration requirements must be met; see Section 27.12.21.5, “The processlist Table” . The  SHOW PROCESSLIST  statement provides process information by collecting thread data from all active threads. The  performance_schema_show_processlist  variable determines which  SHOW PROCESSLIST  implementation to use: Command-Line Format --performance-schema-users-size=# System Variable performance_schema_users_size Scope Global Dynamic No SET_VAR  Hint Applies No Command-Line Format --performance-schema-show- processlist[={OFF|ON}] Introduced 8.0.22 System Variable performance_schema_show_processlist Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --performance-schema-setup-objects- size=# System Variable performance_schema_setup_objects_size Scope Global Dynamic No SET_VAR  Hint Applies No Type Integer Default Value -1  (signifies autoscaling; do not assign this literal value) The number of rows in the  setup_objects  table.