It is the same as recovery on Solaris. Start database and let Oracle try to recover itself. If it fails (because there is more work that SMON knows how to do automatically) then you will get errors about what needs to be recovered. Shutdown the database, restore the files it reported having problems with, then startup mount and issue recover database command.
I recommend taking a cold backup of the "bad" database before you try making it good again. Some people make things worse and need to start recovery over.
Basically I am Oracle developer not a DBA. There is no DBA in the firm anymore so I have to do that recovery by myself. I don't know even any step about Database recovery on NT. I'll really appreciate if you could help me to get backup.
To get back, I have to have a oracle database installed?
what about the environment files? where have to place?
First ... Are the database files currently on the machine and the database just won't come up ??? Did the server die an ugly death and we had to reload ??? ... What's the situation ...
Also, if you still have it, there is an alertxxx.log file in the oracle\admin\xxx\udump (probably) directory ... This is the log that Oracle would write concerning problems... Cut and paste the last couple of pages here ...
Do you know the status of the database? Is it able to mount the control files or not? You check using the below steps. This is important, because sometimes the only "problem" is the database was restarted during a backup and all you need to do is end the backup, not recover anything. Another problem that can occur is you lose just one of your many control files and Oracle refuses to start until you remove the reference to the missing file from your init.ora file (or recreate the file, whichever you prefer.) Again, no recovery would be required.
1. open a command prompt (DOS) window.
2. issue command set oracle_sid=yourdatabasename
3. issue command sqlplus /nolog
4. At the SQL> prompt (which the above command gives you) issue the command CONNECT / AS SYSDBA . If the above command fails, then replace / with SYS/TheSysPassword and try again.
5. Issue the commands select * from v$recovery, select * from v$backup, and select open_mode from v$database.
Also, I highly recommend you look at the alert_SID.log file per the earlier posting by gbrabham.