Oracle Study Guide

1. Trying to start the database using ’startup’ will fail trying to open the datafile. It will give the datafile number let’s say D.

2. Make sure we have backups of all the datafiles. In RMAN type:
REPORT NEED BACKUP REDUNDANCY 1;

If there are datafiles that were not backed up as yet, there are 2 options:
a) delete the datafiles. (RMAN will create them and apply their data from redo logs).
b) issue RMAN command:
BACKUP DATAFILE N;

3. Use RMAN to restore and recover the datafile found missing in step #1. The recovery operation will fail because the online redo is missing.
RESTORE DATAFILE D;
RECOVER DATAFILE D;

4. Find the last log sequence:
SELECT SEQUENCE# FROM V$ARCHIVED_LOG WHERE RECID = (SELECT MAX(RECID) FROM V$ARC
HIVED_LOG);

5. Run the following RMAN script. The nunber X will be 1 more than the number you got from step 4. This is because the UNTIL SEQUENCE clause of RMAN goes to one less than the number specified.

RUN {
SET UNTIL SEQUENCE X THREAD 1;
RESTORE DATABASE;
RECOVER DATABASE;
ALTER DATABASE OPEN RESETLOGS;
}

$ sqlplus "/ as sysdba"

SQL> shutdown immediate

SQL> !mv orig_file target_file
...
SQL> startup mount

SQL> alter database rename file 'orig_file' to 'target_file';
...

    Do not disconnect after this step. Stay logged in
    and proceed to open the database!

SQL> alter database open;

SQL> exit