【多选题】
A Any views created on the EMP table that include the MGR_ID column would be automatically modified and remain valid.
B Any constraints defined on the MGR_ID column would be removed by the above command.
C Any synonym existing on the EMP table would have to be re-created.
D Any index created on the MGR in column would continue to exist until the DROP UNUSED COLUMNS command is executed.
查看更多