Performance Schema Stage Event Tables The  EVENT_ID  value of the event within which this event is nested. The nesting event for a stage event is usually a statement event. The nesting event type. The value is  TRANSACTION ,  STATEMENT ,  STAGE , or  WAIT . The  events_stages_current  table has these indexes: TRUNCATE TABLE  is permitted for the  events_stages_current  table. It removes the rows. The  events_stages_history  table contains the  N  most recent stage events that have ended per thread. Stage events are not added to the table until they have ended. When the table contains the maximum number of rows for a given thread, the oldest thread row is discarded when a new row for that thread is added. When a thread ends, all its rows are discarded. The Performance Schema autosizes the value of  N  during server startup. To set the number of rows per thread explicitly, set the  performance_schema_events_stages_history_size  system variable at server startup. The  events_stages_history  table has the same columns and indexing as events_stages_current . See Section 27.12.5.1, “The events_stages_current Table” . TRUNCATE TABLE  is permitted for the  events_stages_history  table. It removes the rows. For more information about the relationship between the three stage event tables, see Section 27.9, “Performance Schema Tables for Current and Historical Events” . For information about configuring whether to collect stage events, see Section 27.12.5, “Performance Schema Stage Event Tables” . The  events_stages_history_long  table contains the  N  most recent stage events that have ended globally, across all threads. Stage events are not added to the table until they have ended. When the table becomes full, the oldest row is discarded when a new row is added, regardless of which thread generated either row. The Performance Schema autosizes the value of  N  during server startup. To set the table size explicitly, set the  performance_schema_events_stages_history_long_size  system variable at server startup. The  events_stages_history_long  table has the same columns as  events_stages_current . See Section 27.12.5.1, “The events_stages_current Table” . Unlike  events_stages_current , events_stages_history_long  has no indexing. TRUNCATE TABLE  is permitted for the  events_stages_history_long  table. It removes the rows. For more information about the relationship between the three stage event tables, see Section 27.9, “Performance Schema Tables for Current and Historical Events” . For information about configuring whether to collect stage events, see Section 27.12.5, “Performance Schema Stage Event Tables” . 4969 27.12.5.3 The events_stages_history_long Table 27.12.5.2 The events_stages_history Table • NESTING_EVENT_TYPE •Primary key on ( THREAD_ID ,  EVENT_ID )