例子：
SQL> set linesize 300
SQL> select * from V$RECOVERY_AREA_USAGE;
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES CON_ID
--------------------------------------------------------------------- ------------------ ------------------------- --------------- ----------
CONTROL FILE .09 0 1 0
REDO LOG 1.46 0 3 0
ARCHIVED LOG 0 0 0 0
BACKUP PIECE 0 0 0 0
IMAGE COPY 0 0 0 0
FLASHBACK LOG 0 0 0 0
FOREIGN ARCHIVED LOG 0 0 0 0
AUXILIARY DATAFILE COPY 0 0 0 0