Archive Log Mode during Hot Backups

[vnktummala]

hot backups?.(i am not concerned about restore and recover but only about hot backup process)

you SHOULD concern about restore and recover when are you trying to take the hot backup. Because, hot backup is not consistent and in case of recovery you should need archive logs to get back your data.

Thanks,

[PAVB]

...why it is compulsary to put database in archive log mode during hot backups?.(i am not concerned about restore and recover but only about hot backup process)

The answer is pretty simple -providing you are not using RMAN you must put your tablespaces in backup mode, otherwise the backup you may take will be unrecoverable.

As you may remember in order to recover from a Hot Backup you have to do two different things...
1- Restore your Hot Backup
2- Recover the database -here is where archivelogs enter in the picture.
How does Oracle knows what has to be recovered from archivelogs?... looking at the SCN. If you never put your tablespace in backup mode SCN would not be frozen then Oracle wouldn't know what has to be recovered.

Hope this clarifies.