How cloning from backup became a little more secure in Oracle 11g

From version 11, Oracle supplied another method to use during cloning, namely "Backup-based duplication without a target connection".

From the Oracle 11g Documentation:

RMAN can perform the duplication in any of the following supported modes:

1.       Active duplication
2.       Backup-based duplication without a target connection
3.       Backup-based duplication with a target connection
4.       Backup-based duplication without connection to target and recovery catalog

If you choose method number 2, you need to use the following syntax:

DUPLICATE DATABASE <target database> TO <auxiliary database>;

In the 10g documentation you will need to use the "target" keyword

DUPLICATE TARGET DATABASE TO <auxiliary database>;

Oracle points out:

«This mode is useful when the target database is not available or a connection to it is not desirable». 

In other words, cloning has become more secure since version 11g, where we can totally avoid connecting to the target database, which is often in production, during cloning from backup.

An example of an incident where a connection to the target could potentially jeopardize production, is when you are scripting jobs for RMAN and accidently issue "shutdown", which will bring down your target database and not your auxiliary database, which was what you intended.

For the record, the keyword "target" is an unfortunate choice of syntax during cloning. In IT, a "target" would generally be interpreted as a synonym for "destination", which is where you want to clone *TO*.