Adding a datafile

SQL> alter tablespace venu

     add

     datafile '/u03/app/oracle/ssss/venu02.dbf' size 5m;

SQL> select name from v$tablespace;

note : we need to specify the size of the tablespace compulsorily.

SQL> select tablespace_name,file_name,file_id from dba_data_files where tablespace_name='venu';