The primary database can be either a single-instance Oracle database or an Oracle Real Application Clusters (RAC) database. Similar to a primary database, a standby database can be either a single-instance Oracle database or an Oracle RAC database.
My question is it feasible to have my standby database as single instance while the primary is RAC?Yes...quite a common setup.
is it feasible to build my Oracle single instance standby database from the RMAN backup of the RAC primary database?Yes.
Is there any restrictions (or any points to be taken into consideration) since my primary database is RAC while the physical standby is Oracle single instance?No show stoppers.