SVRMGR> select file_name,tablespace_name,bytes from dba_data_files;
FILE_NAME TABLESPACE_NAME BYTES
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/home/oracle/oradata/RUSH/tools01.dbf
TOOLS 10485760
/home/oracle/oradata/RUSH/drsys01.dbf
DRSYS 20971520
/home/oracle/oradata/RUSH/users01.dbf
USERS 20971520
/home/oracle/oradata/RUSH/indx01.dbf
INDX 20971520
/home/oracle/oradata/RUSH/rbs01.dbf
RBS 52428800
/home/oracle/oradata/RUSH/temp01.dbf
TEMP 20971520
/home/oracle/oradata/RUSH/system01.dbf
SYSTEM 293601280
/home/oradata/data01.dbf
BACKRUSH 1048576000
8 rows selected.
SVRMGR>

BACKRUSH라는 tablespace에는 data01.dbf라는 데이타파일
1G이 전부임을 확인할수있다.