select ID,KEY1,( select VALUE1 from TABLE2 t2 where t2.KEY1 = t1.KEY1) as VALUE1 ,KEY2,( select VALUE2 from TABLE3 t3 where t3.KEY2 = t1.KEY2) as VALUE2 ,VALUEx from TABLE1 t1
select t1.ID,t1.KEY1,t2.VALUE1,t1.KEY2,t3.VALUE2,t1.VALUEx from TABLE1 t1,TABLE2 t2,TABLE3 t3 where t1.KEY1 = t2.KEY1(+) and t1.KEY2 = t3.KEY2(+) and ti.id = ...
from TABLE1 t1,TABLE2 t2,TABLE3 t3
where t1.KEY1 = t2.KEY1(+)
and t1.KEY2 = t3.KEY2(+)
and ti.id = ...