多项选择题
A. You must ensure that the SALES database is mounted or open.
B. You must restore a backup control file to perform a block media recovery.
C. You must take the tools01.dbf data file offline before you start a block media recovery.
D. You must put the database in NOARCHIVELOG mode to perform a block media recovery.
E. You can perform only a complete media recovery of individual blocks， point-in-time recovery of individual data blocks is not supported.
单项选择题 Oneofthetablespacesisread-onlyinyourdatabase.Thelossofallcontrolfilesforcedyoutore-createthecontrolfile.Whichoperationdoyouneedtoperformafterre-creatingthecontrolfileandopeningthedatabase？（）
单项选择题 Youobservethatadatabaseperformancehasdegradedoveraperiodoftime.Whileinvestigatingthereason，youfindthatthesizeofthedatabasebuffercacheisnotlargeenoughtocachealltheneededdatablocks.Whichadvisorycomponentwouldyoureferto，inordertodeterminethatrequiredsizeofthedatabasebuffercache？（）