单项选择题
A.v$sessionB.dba_hist_active_sess_historyC.wrh$_active_session_historyD.v$database
A.exclusiveB.shareC.row-XD.row-S
A.执行以下命令重建redo组:alter database clear logfile group 1B.删除对应的redo组,然后重建C.恢复数据库到故障前D.切换redo组