Adding more than one Datafile to an Oracle Tablespace

If you need to add an additional data file to an Oracle Tablespace:

ALTER TABLESPACE 
   users 
ADD DATAFILE 
   'AdditionalUsersTablespace.dbf' 
size 100m
AUTOEXTEND ON
NEXT 10M


More info from these posts:

http://www.dba-oracle.com/t_alter_tablespace_add_datafile.htm

http://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_3002.htm