database recovery failed -- access to database denied by monitor

  Explanation:  To maintain the integrity of the database, the
  monitor forced your image exit because an unrecoverable error
  has been detected.

  User Action:  Look for a file named SYS$SYSTEM:*DBRBUG.DMP.
  This is a DataBase Recovery process bugcheck dump.  Search the
  file for a string of five asterisks (*****) using the
  SEARCH/WINDOW command.  You will see a line with a format
  similar to this:  ***** Exception at <address> :  <database
  module name> + <offset> %facility-severity-text, <error text>
  The exception line will be followed by one or more additional
  errors that will help you to determine what caused the recovery
  process to fail.  Possible causes include:  low quotas, missing
  Recovery-Unit Journal (RUJ) files, or filename logicals
  misdefined or undefined.  Depending on the cause of the problem,
  take the appropriate action.  If you are uncertain of what to
  do, contact your Oracle support representative for assistance.