ALTER TABLESPACE USERS ADD DATAFILE
'/u01/app/oracle/oradata/orcl/savefile.dbf' SIZE 10G
AUTOEXTEND ON NEXT 200M;
CREATE TABLESPACE USERS DATAFILE '/home/oracle/oracle/product/10.2.0/oradata/as/users01.dbf' SIZE 500M REUSE AUTOEXTEND ON NEXT 500M MAXSIZE UNLIMITED;
ALTER TABLESPACE USERS ADD DATAFILE '/u01/app/oracle/oradata/pf/users02.dbf' SIZE 500M REUSE AUTOEXTEND ON NEXT 500M MAXSIZE UNLIMITED;
shrink tablespace
https://forums.oracle.com/forums/thread.jspa?threadID=923890