Performance Schema Summary Tables The Performance Schema maintains tables for collecting current and recent transaction events, and aggregates that information in summary tables. Section 27.12.7, “Performance Schema Transaction Tables”  describes the events on which transaction summaries are based. See that discussion for information about the content of transaction events, the current and historical transaction event tables, and how to control transaction event collection, which is disabled by default. Example transaction event summary information: Each transaction summary table has one or more grouping columns to indicate how the table aggregates events. Event names refer to names of event instruments in the  setup_instruments  table: These columns are analogous to the columns of the same names in the wait event summary tables (see Section 27.12.20.1, “Wait Event Summary Tables” ), except that the transaction summary tables aggregate events from  events_transactions_current  rather than  events_waits_current . These columns summarize read-write and read-only transactions. 5061 • COUNT_READ_WRITE ,  SUM_TIMER_READ_WRITE ,  MIN_TIMER_READ_WRITE , AVG_TIMER_READ_WRITE ,  MAX_TIMER_READ_WRITE • COUNT_STAR ,  SUM_TIMER_WAIT ,  MIN_TIMER_WAIT ,  AVG_TIMER_WAIT ,  MAX_TIMER_WAIT • events_transactions_summary_global_by_event_name  has an  EVENT_NAME  column. Each row summarizes events for a given event name. Each transaction summary table has these summary columns containing aggregated values: • events_transactions_summary_by_user_by_event_name  has  USER  and  EVENT_NAME columns. Each row summarizes events for a given user and event name. • events_transactions_summary_by_thread_by_event_name  has  THREAD_ID  and  EVENT_NAME columns. Each row summarizes events for a given thread and event name. • events_transactions_summary_by_host_by_event_name  has  HOST  and  EVENT_NAME columns. Each row summarizes events for a given host and event name. • events_transactions_summary_by_account_by_event_name  has  USER ,  HOST , and EVENT_NAME  columns. Each row summarizes events for a given account (user and host combination) and event name. mysql>  SELECT * FROM performance_schema.events_transactions_summary_global_by_event_name LIMIT 1\G *************************** 1. row *************************** EVENT_NAME: transaction COUNT_STAR: 5 SUM_TIMER_WAIT: 19550092000 MIN_TIMER_WAIT: 2954148000 AVG_TIMER_WAIT: 3910018000 MAX_TIMER_WAIT: 5486275000 COUNT_READ_WRITE: 5 SUM_TIMER_READ_WRITE: 19550092000 MIN_TIMER_READ_WRITE: 2954148000 AVG_TIMER_READ_WRITE: 3910018000 MAX_TIMER_READ_WRITE: 5486275000 COUNT_READ_ONLY: 0  SUM_TIMER_READ_ONLY: 0  MIN_TIMER_READ_ONLY: 0  AVG_TIMER_READ_ONLY: 0  MAX_TIMER_READ_ONLY: 0