Query on view - IS the querry executed each time view is referred?

Question

I want to know whether query inside a view is executed each time when the view is being referred?
Also which on of below will be faster?
select
     a1.x,
     a1.y,
     b1.z
from
     TableA a1,
     TableB b1
where
     a1.keyName = 'F' || b1.someKey
OR     
cretae view myView as
select
     'F' || someKey as anotherKey
from
     TableB
select
     a1.x,
     a1.y,
     b1.z
from
     TableA a1,
     myView b1
where
     a1.keyName = b1.anotherKey

Answer 1

A view is just a stored query, so it has to be executed each time it is referenced in a query.
The two queries should have identical performance. It might be vanishingly faster to parse the first query than the second, but I doubt you would be able to detect the difference.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC