686. You execute the following FLASHBACK TABLE command: Which two statements are correct?(Choose two.)
A.The EMP table that was dropped by mistake earlier is restored.
B.The FLASHBACK TABLE statement is executed as a single transaction.
C.The FLASHBACK TABLE statement does not maintain existing indexes on the EMP table.
D.The changes made to the EMP table since the specified time are undone if no constraint is violated during flashback.
正确答案是BD