loss of current online redo log group.

When you lost current online redo log(media failure) , you need to perform incomplete recovery.
Oracle says restore all data files and redo log files from the backup.
Under the 24 by 7 database, I can only make hot backups, in other words, I don't have redo log backups.
Does this mean I can not recover from this type of failure?
Please share your experience with me.

you perform incomplete recovery with archived logs and recover until last redo log if you can
What you say about Oracle is when your database is in noarchive log mode

You can only recover through your last archived redo log. Since you are not archiving, you can not recover.

Since you say that you are taking hot backups you should be in Archivelog mode.You can restore the database until the online redolog file that is lost (until cancel) and open the database with resetlogs option.

what I want to know is if I need to restore online redo logs or not to perform this kind of recovery. As you know, you can not restore online redo log from hot backukp.
According to you guys, all I need to do is restore all data files from backup, and recover database until cancel.
Is this right?

yes, but do you know the difference between archived log and online redo logs...? Seems like you have a bit confusion why we dont have to backup online redo logs in hot backups

absolutely.

In Oracle backup and recovery book ( from Oracle University ) , It says restore all data file and redo log file, So I was confused.

[/B][/QUOTE] restore all data file and redo log file, So I was confused. [/B][/QUOTE]

Well you restore a cold backup if you are in noarchive log mode which means you have to restore datafiles and redo log files

Somehow, I thought the case in the book is about the database in the archive log mode.
All my fault.
Nothing better than actuall test.
I just tested recovery from hot backup when the current online redo log has a problem, due to the media failure.
I restored all data files (no redo logs) and issued
'recover database until cancel' it worked.
Thanks you for all your help.