Which three are true about requirements for various FLASHBACK operations? (Choose three.)
A.FLASHBACK transaction query requires undo to retrieve all versions of a row that existed between two points in time. B.FLASHBACK drop requires that the RECYCLEBIN parameter be set to ON. C.FLASHBACK version query requires that the RECYCLEBIN parameter be set to ON. D.FLASHBACK DATA ARCHIVE requires undo to store all versions of all rows of a table being tracked. E.FLASHBACK drop requires undo to retrieve all versions of a row that existed between two points in time. F.FLASHBACK version query requires undo to retrieve all versions of a row that existed between two points in time.正确答案ABF
