SYS>desc dba_data_files;
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE_NAME VARCHAR2(257)
FILE_ID NUMBER
TABLESPACE_NAME VARCHAR2(30)
BYTES NUMBER
BLOCKS NUMBER
STATUS VARCHAR2(9)
RELATIVE_FNO NUMBER
AUTOEXTENSIBLE VARCHAR2(3)
MAXBYTES NUMBER
MAXBLOCKS NUMBER
INCREMENT_BY NUMBER
USER_BYTES NUMBER
USER_BLOCKS NUMBER
ONLINE_STATUS VARCHAR2(7)

SYS> select file_name,autoextensible from dba_data_files;