View is very slow.

Question

Hi All,
I have a view which has 15 select statement using union. It's a complex view.
create or replace view v1 (c1,c2,c3)
as
select c1,c2,c3 from t1,t20,t30,t40 where ...............
union
select c1,c2,c3 from t2,t3,t4,t5 where ...............
union
select c1,c2,c3 from t15,t16,t,17 where ...............
If I run the select statement on its own its very quick, records are retrieved in milli seconds.
select c1,c2,c3 from t1,t20,t30,t40 where c1 = xyz
union
select c1,c2,c3 from t2,t3,t4,t5 where c1 = xyz
union
select c1,c2,c3 from t15,t16,t,17 where c1 = xyz
but If I run the same selects through a view then it takes 10 min.
select * from v1 where c1 = xyz
Can someone tell me whats the difference,why the view is so slow as its the same sql in a view and if there is a work around.I have to make this view run faster as its used in Oracle forms.
Thanks.
V.

Answer 1

I tried doing UNION ALL and ran the same query it made no difference. It took still 10 min, which means whether its union or union all oracle is not able to push the predicate inside the various sub queries . Thanks Rob.
Any other solutions ?
I think I may have to take the select statments from the view and create the form based on the proecudure using the select statements.
V.