In response to "Mendola Gaetano":
> I'm running Postgres7.3.3 and I'm performing this simple select:
Looking at your fast three step plan
> SELECT id_class from class_default where id_provider = 39;
> SELECT id_user from user_data where id_class in ( 48 );
> SELECT * from user_logs where id_user in (
> 10943, 10942, 10934, 10927, 10910, 10909 );
I'ld stem for reordering the from and where clauses alike:
select *
from
class_default cd,
user_data ud,
user_logs ul
where
cd.id_provider = 39 and
ud.id_class = cd.id_class and
ul.id_user = ud.id_user;
Personally I dislike implied joins and rather go for _about_ this:
select *
from
( class_default cd
LEFT JOIN user_data ud ON ud.id_class = cd.id_class )
LEFT JOIN user_logs ul ON ul.id_user = ud.id_user,
where
cd.id_provider = 39;
Good luck,
HansH
