V$TRANSPORTABLE_PLATFORM displays all platforms that support cross-platform tablespace transport. Specifically, it lists all platforms supported by the RMAN CONVERT TABLESPACE command, along with the endianness of each platform.
Platform identification number
Platform endian format:
The ID of the container to which the data pertains. Possible values include:
0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data