Recovery Manager Advanced Techniques - Oracle 10g/11g Data and Database Management Utilities - page 93

Format Mask Description

%f Specifies the absolute file number

%F

Combines the Database ID ( DBID ), day, month, year, and sequence into
a unique and repeatable generated name

%h Specifies the archived redo log thread number

%I

Specifies the DBID

%M

Specifies the month in the Gregorian calendar in MM format

%N Specifies the tablespace name

%n Specifies the name of the database, padded on the right with n characters

to a total length of eight characters

%p

Specifies the piece number within the backup set

%s

Specifies the backup set number

%t

Specifies the backup set timestamp

%T Specifies the year, month, and day in the Gregorian calendar

%u Specifies an eight-character name constituted by compressed

representations of the backup set or image copy number

%U

Specifies a system-generated unique filename (this is the default setting)

What happens in a user-managed online
backup?
There are two ways to perform a backup; the offline backup and the online backup :
The first one is performed when the database has been cleanly shutdown (normal,
immediate or transactional). The second one is performed when the database is open.

The offline database backup does not require the database to be in archivelog mode;
meanwhile the online database backup requires the database to be in archivelog
mode. An online backup is usually preferable to an offline backup, as an online
backup does not require the database to be shutdown.

For the DBA to be able to perform a recoverable online backup the database must be
in archivelog mode. The backup can be performed either as a user managed backup
or an RMAN managed backup. When the backup starts, Oracle issues a checkpoint
operation against the datafile, this flushes all target related database blocks to the
datafiles belonging to the tablespace; afterwards the datafile header is frozen.