System Administrator’s Guide U42252-J-Z915-1-76
5 Recovery
This chapter describes the various ways in which you can carry out a recovery
for an ORACLE database.
We recommend you try out a recovery of your database on a test system.
This will enable you to become familiar with the possible procedures, so
that in a genuine emergency you will be in a position to decide which type
of recovery is appropriate.
There are basically three ways of recreating a damaged ORACLE database:
●firstly, performing a complete fully-automatic recovery of the entire database
with the nsrora_rec command
●secondly, performing a recovery until time with the ora_recut command for an
optional point in time between the first full_save backup and the point in time
the recent changes within the database have occured.
●thirdly, carrying out a manual recovery, in which the corrupted data is
restored by hand.

5.1 Selecting the Type of Recovery

Which type of recovery you choose (recover until time, automatic or manual) will
depend entirely on the actual situation. There are advantages and disadvan-
tages to all methods; you will have to weigh these up as appropriate for the
specific circumstances. This section is intended to help you decide whether to
perform an specific type of recovery.

5.1.1 The Recovery Component

The NSR-ORA recovery component allows the automatic recovery of an
ORACLE database saved with NSR-ORA if one or more database file(s) are lost
or an logical error has occurred (see figure 6 following).
i