ALTER DATABASE OPEN RESETLOGS|NORESETLOGS

July 20, 2009
KeyWord: ORACLE DATABASE, RESETLOGS, NORESETLOGS
  RESETLOGS | NORESETLOGS This clause determines whether Oracle Database resets the current log sequence number to 1, archives any unarchived logs (including the current log), and discards any redo information that was not applied during
recovery, ensuring that it will never be applied.
  Oracle Database uses NORESETLOGS automatically except in the following specific situations, which require a setting for this clause:
  1. You must specify RESETLOGS:
   – After performing incomplete media recovery or media recovery using a backup controlfile
   – After a previous OPEN RESETLOGS operation that did not complete
   – After a FLASHBACK DATABASE operation
  2. If a created controlfile is mounted, then you must specify RESETLOGS if the online logs are lost, or you must   specify NORESETLOGS if they are not lost.