Which statement is true regarding online redefinition for the migration of BasicFile LOBs to SecureFile LOBs?
A. It cannot be done in parallel.
B. It can be done at the table level or partition level.
C. It does not require additional storage because the operation is done online.
D. Local and global indexes are maintained automatically during the operation.
SecureFile LOBs 加密的，所以空间开销肯定更大
参考 http://blog.itpub.net/53956/viewspace-1299822/
迁移示范 http://www.wangchao.net.cn/it/detail_53154.html