hi,

i have this query:

select
cu.id_cuenta
from cuenta cu
join notificacion nt on nt.id_cuenta = cu.id_cuenta

and i get this plan:

PLAN JOIN (NT NATURAL,CU INDEX (RDB$PRIMARY1))

table cuenta has a pk on id_cuenta
table notificacion has a fk on id_cuenta

why optimizer choses natural instead fk on notificacion?
is related to record count?

tia,
mariano