Which three are true about patchsets? (Choose three.)
A.正确答案BDFThey can be applied in a rolling fashion for Clusterware and the databases.
B.They can introduce new features.
C.They are installed via OPatch or OPatchAuto.
D.Installing a patchset is considered an 'upgrade'.
E.They are only released quarterly. F.A base release is not needed to install patchsets.