Because RMU Repair cannot correct every type of corruption, or
    guarantee improved performance, Oracle Corporation recommends
    that you do not use the RMU Repair command unless you have a
    backup copy or exported copy of your database. You can return
    to this backup copy of the database if your repair efforts are
    ineffective.

    The RMU Repair command operates off line and not in the context
    of a transaction, so no records are written to the database's
    .aij file by RMU Repair, and the repaired database cannot be
    rolled forward with the RMU Recover command. Oracle Corporation
    recommends that you make a backup copy of the database after
    using the RMU Repair command; the repair operation issues a
    message to this effect. Oracle RMU also issues a warning when
    you use this command on a database with after-image journaling
    enabled.