Server System Variables uses existing index statistics instead of index dives if there are  eq_range_index_dive_limit or more equality ranges. Thus, to permit use of index dives for up to  N  equality ranges, set eq_range_index_dive_limit  to  N  + 1. To disable use of index statistics and always use index dives regardless of  N , set  eq_range_index_dive_limit  to 0. For more information, see Equality Range Optimization of Many-Valued Comparisons. To update table index statistics for best estimates, use  ANALYZE TABLE . The number of errors that resulted from the last statement that generated messages. This variable is read only. See Section 13.7.7.17, “SHOW ERRORS Statement” . • error_count • event_scheduler Command-Line Format --event-scheduler[=value] System Variable event_scheduler Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Enumeration Default Value ON Valid Values ON OFF DISABLED This variable enables or disables, and starts or stops, the Event Scheduler. The possible status values are  ON ,  OFF , and  DISABLED , with the default being  OFF . Turning the Event Scheduler  OFF  is not the same as disabling the Event Scheduler, which requires setting the status to  DISABLED . This variable and its effects on the Event Scheduler’s operation are discussed in greater detail in Section 25.4.2, “Event Scheduler Configuration” • explicit_defaults_for_timestamp Command-Line Format --explicit-defaults-for- timestamp[={OFF|ON}] Deprecated Yes System Variable explicit_defaults_for_timestamp Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value ON This system variable determines whether the server enables certain nonstandard behaviors for default values and  NULL -value handling in  TIMESTAMP  columns. By default, 797