Backups when the DB in NOARCHIVELOG

Question

Hi
Assume the DB is in NOARCHIVELOG mode
Is it possible to
- back up the SYSTEM tablespace in your database when the database is open?
- backup a read-only tablespace even when the database is open?
- back up a dictionary-managed tablespace even when the database is open?
(It says:
A dictionary-managed tablespace can be backed up by placing the tablespace in the online backup mode and copying the corresponding datafiles.)- What is meant by 'online backup mode'?
-IS it possible to backup a datafile, either the relavent tablespace is online/offline/read only
Thanks
Edited by: Zerandib on Sep 25, 2008 2:03 PM
Edited by: Zerandib on Sep 25, 2008 2:16 PM

Answer 1

Hi,
Online Backup Mode:
Tablespace Backup:
Each tablespace that needs to be backed-up must be switched into backup mode before copying the files out . Look at this simple example:
ALTER TABLESPACE test BEGIN BACKUP;
! cp db_test_01.dbf /backupDir/
ALTER TABLESPACE test END BACKUP;
Database Backup:
Since 9i you can do it at DB level:
Alter database begin backup;
-then copy all the files
Alter database end backup;
Don forget to make a copy of the controlfile too:
ALTER SYSTEM SWITCH LOGFILE;   -- Force log switch to update control file headers      
ALTER DATABASE BACKUP CONTROLFILE TO '/backup/control.dbf';Cheers,
Francisco Munoz Alvarez
http://www.oraclenz.com