Cross-platform Data Guard was introduced in Oracle 11g Release 1. We may have 32-bit primary and 64-bit standby database combinations on some platforms of 10g, but from 11g onwards it supports even heterogeneous platforms ranging from Linux/Unix to Windows or vice versa. Most of the customers choose this procedure for moving the database on a different OS. Migration is made simple by this procedure with the same incarnation of a database. Prior to moving the production to a heterogeneous platform, it is recommended to test the standby in the read-write mode for the capacity of the standby server.

Note that you must create a cross-platform standby database on the same database's release and patch set. You can have different hardware manufacturers, hardware configuration, processors, operating systems, and operating system versions. From 11g onwards you can configure Data Guard broker between the cross-platforms, and you can configure the cross-platform standby by using the Oracle grid manager also.