About hot & cold backups in rman

Question

Hi all,
I've found out that with rman 9i the following script:
- shutdown immediate;
- startup mount;
- backup database plus archivelog;
- alter database open;
is what I need for a cold backup; somewhere somehow I've caught a glimpse about
this script
- backup database plus archivelog;
which 'should' be able to produce a reliable hot backup, but actually Oracle docs
is not crystal clear on this point: I'd rather ask if:
a/ would "backup database plus archivelog" create an usable full backup on
a 9i archivelogged db?
b/ would the same statement work on a 8.1.7 archivelogged db? (yes, the syntax is different...)
hope somebody may shed some light
thanks for help,
daniele rizzi ([email protected])

Answer 1

backup database plus archivelog; is a 9i RMAN command so it cannot be used in 8i. Here is what it does as stated in the Oracle9i Recovery Manager User's Guide and Reference:
Backing Up Logs Using BACKUP ... PLUS ARCHIVELOG
When backing up objects other than archived logs, you can specify BACKUP ... PLUS ARCHIVELOG to include backups of archived logs. The command performs the following sequential actions:
- Runs the ALTER SYSTEM ARCHIVE LOG CURRENT command.
- Runs BACKUP ARCHIVELOG ALL. Note that if backup optimization is enabled (refer to "Backing Up Files Using Backup Optimization"), then RMAN skips logs that it has already backed up to the specified device.
- Backs up files specified in BACKUP command.
- Runs the ALTER SYSTEM ARCHIVE LOG CURRENT command.
- Backs up any remaining archived logs generated during the backup.
From what I read it backs up all current archivelogs, backs up the datafiles, and backs up any remaining archivelogs created during the datafile backup. It basically makes it easier to backup the archivelogs by not having to issue a archvielog backup before and after the datafiles to ensure all archivelogs are backed up.