Hi All,

I need a expert help in recovering my database.

Currently I am preparing for my DBA Fundamentals II exam. To test the db recovery process, I corrupted my database by deleting a datafile.

I have Oracle 9i installed in Windows XP. By default, as archiving is disabled i thought my database is running under NOARCHIVELOG Mode. I took a cold backup by just copying all the files like control, redo logs, data files to another directory. But actually i did changed the database to ARCHIVELOG mode sometime back and I totally forgot about it.

Then logged in and added some data to some table. Then stopped the database and removed a datafile and tried to restart the database again and got the error "ORA-01157: Cannot identify/lock data file 4 - see DBWR trace file".

As I had an idea that the db is running under NOARCHIVELOG mode. I just unmounted the db and copied the backup files from the backup directory to the data directory and tried restarting again.

D:\Profiles\e4007z>sqlplus /nolog

SQL*Plus: Release 9.0.1.0.1 - Production on Sun Jun 3 12:25:55 2007

(c) Copyright 2001 Oracle Corporation. All rights reserved.

SQL> connect sys as sysdba
Enter password:
Connected to an idle instance.
SQL> startup
ORACLE instance started.

Total System Global Area 118255568 bytes
Fixed Size 282576 bytes
Variable Size 83886080 bytes
Database Buffers 33554432 bytes
Redo Buffers 532480 bytes
Database mounted.
ORA-01092: ORACLE instance terminated. Disconnection forced

I got the above error message.

I need the expert help to identify the better way to restore my database back.

Thanks in advance.