DBA_LOGSTDBY_EVENTS

Information on why logical standby events

Columns
   ___________________________
 
   EVENT_TIME
      Time the event took place
   CURRENT_SCN
      Change vector SCN for the change
   COMMIT_SCN
      SCN for the commit record of the transaction
   XIDUSN
   XIDSLT
   XIDSQN
   EVENT
      A SQL statement or other text describing the event
   STATUS_CODE
      A number describing the event
   STATUS
      A text string describing the event

Related:

DBA_LOGSTDBY_SKIP_TRANSACTION