Please review the following if you haven't already: Secure file Migration and Accessing securefile metadata information [Video] (Doc ID 1170351.1)
We can easily migrate from a Basicfile to Secure file LOBS.The two recommended methods for migration to securefiles are Partition exchange and online redefinition.
1] Partition Exchange
. Needs additional space equal to the largest of the partition in
. Can maintain indexes during the exchange.
. Can spread the workload out over several smaller maintenance
. Required that the table or Partition needs to be offline to
perform the exchange.
2] Online Redefinition
. No need to take the table or partition offline.
. Can be done in parallel.
. Requires additional storage equal to the entire table and all
LOB segments to be available.
. Requires that any global indexes to be rebuilt.
Online redefinition is the recommended method. However, Using portioning and taking these actions on a partition-by-partition basis may be help lower the disk space required.
However, Oracle documentation 11.2 says "Online redefinition is the only recommended method for migration of BasicFiles LOBs to SecureFiles LOBs."
Please advise if there are any know issues for using " Alter table <tablename> move lob" to convert from basicfile to securefile.
It may be no issues. However it is undocumented and not recommended way. If you will get into issues, most likely you will be on your own, most likely Oracle support will not help you, they will ask you to make migration "the proper way".