CREATE TABLESPACE hr_tablespace
DATAFILE '+DATA001/App/DATAFILE/datafile.001.0000001' SIZE 60M AUTOEXTEND ON NEXT 10M MAXSIZE UNLIMITED

select tablespace_name, 
       FILE_NAME, 
       BYTES/(1024*1024) filesize, 
       MAXBYTES/(1024*1024) maxbytes, 
       increment_by/(1024*1024) increment_by, 
       AUTOEXTENSIBLE 
  from DBA_DATA_FILES
 where tablespace_name;

SQL> desc DBA_DATA_FILES
 Name                             Null?    Type
 -------------------------------- -------- ----------------------
 FILE_NAME                                 VARCHAR2(513)
 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)