You have not configured Oracle Managed Files (OMF) in your database. You do not want to scan the entire datafile every time an incremental backup is performed. You decide to enable the block change tracking feature. Which statement should you use to enable the block change tracking feature?
A. ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
B. ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING USING FILE <path>;
C. ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE <path>;
D. ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING;
在使用 OMF（由参数 DB_CREATE_FILE_DEST 控制）的情况下，可以使用如下命令启用块跟踪：
ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
如果不使用 OMF，可以使用如下命令，其中 REUSE 可以重用存在的文件：
ALTER DATABASE ENABLE BLOCK CHANGE TRACKING
USING FILE '/mydir/rman_change_track.f' REUSE;