svrmgr>create tablespace tbs1 datafile 'nombre_fichero.dbf' size 10m default storage (initial 50k next 25k pctincrease 0) online;
svrmgr>alter tablespace tbs1 add datafile 'otro_fichero.dbf' size 10m;
svrmgr>alter database datafile 'fichero.dbf' resize 150m;
create table t1 (...) tablespace tbs1;