The size of the export file may be limited by operating system restrictions (the limit is typically 2GB in many Unix systems).

You cannot explicitly export or import objects other than tables. However, these objects are processed automatically when doing user or full database exports or imports.

After a table is imported, its indexes must be rebuilt. (Import can do this automatically.)

Each table exported is a separate transaction. In order to get a consistent backup, you need to specify the CONSISTENT=Y parameter in the control file. However, for large or active databases, you then run the risk of getting a “snapshot too old” error message.