Case 1: Recover from corrupted or missing data file
This scenario deal with a situation where data file has gone missing or corrupted at the time of open the database.
This scenario deals with a situation where a datafile has gone missing, or is corrupted beyond repair. For concreteness, we look at a case where a datafile is missing. Below is a transcript of an SQL Plus session that attempts to open a database with a missing datafile (typed commands in bold, lines in italics are my comments, all other lines are feedback from SQL Plus):
–open SQL Plus from the command line without
–logging on to database
C:>sqlplus /nolog
SQL*Plus: Release 9.2.0.4.0 – Production on Tue Jan 25 14:52:41 2005
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
–Connect to the idle Oracle process as a privileged user and start up instance
SQL> connect / as sysdba
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 131555128 bytes
Fixed Size 454456 bytes
Variable Size 88080384 bytes
Database Buffers 41943040 bytes
Redo Buffers 1077248 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 4 – see DBWR trace file
ORA-01110: data file 4: ‘D:ORACLE_DATADATAFILESORCLUSERS01.DBF’
ORA-01110: data file 4: ‘D:ORACLE_DATADATAFILESORCLUSERS01.DBF’
SQL>
The error message tells us that file# 4 is missing. Note that although the startup command has failed, the database is in the mount state. Thus, the database control file, which is also the RMAN repository can be accessed by the instance and by RMAN. We now recover the missing file using RMAN. The transcript of the recovery session is reproduced below (bold lines are typed commands, comments in italics, the rest is feedback from RMAN):
–logon to RMAN
C:>rman target /
Recovery Manager: Release 9.2.0.4.0 – Production
Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
connected to target database: ORCL (DBID=1507972899)
–restore missing datafile
RMAN> restore datafile 4;
–recover restored datafile – RMAN applies all logs automatically
RMAN> recover datafile 4;
media recovery complete
–open database for general use
RMAN> alter database open;
database opened
RMAN>
Responses