单项选择题 To reference existing ASM files， you need to use a fully qualified ASM filename. Your development database has a disk group named DG2A， the database name is DEV19， and the ASM file that you want to reference is a datafile for the USERS02 tablespace.  Which of the following is a valid ASM filename for this ASM file？（）

单项选择题 HowcanyoureversetheeffectsofanALTERDISKGROUP...DROPDISKcommandifithasnotyetcompleted？（）

单项选择题 You want to migrate your database to ASM， so you have done a clean shutdown， made a closed backup of the entire You wa database， noted the location of your control files and online redo log files， and changed your spfile to use OMF. The last step is to run an RMAN script to do the conversion.  Using the following steps，what is the correct order in which the following RMAN commands should be executed？（）   1. STARTUP NOMOUNT  2. ALTER DATABASE OPEN RESETLOGS  3. SQL "ALTER DATABASE RENAME ，，logfile1 path TO ，，+dgrp4 ，，" # plus all other logfiles  4. SWITCH DATABASE TO COPY  5. BACKUP AS COPY DATABASE FORMAT ，，+dgrp4 6. ALTER DATABASE MOUNT  7. RESTORE CONTROLFILE FROM ，，controlfile_location