whos could be much efficient if I use `nestted subquery`, `JOINs` Or maybe `temp tables` ..
another question : in subqueries if i use IN Clause twice with the same query it should be execute a twice too !? like this : 

```
Select ...
From X 
Where Exists( Select 1  From Y Where Idx = Y.SomeColumn ) 
Or Exists( Select 1 From Y Idy = Y.SomeColumn )

```

how many times the sub-query `SELECT * FROM Y` could be executed in this query !  

and what if I use this way to do so : 

```
With XX As
(
Select ...
From Y
)
Select ...
From X
Where Exists ( Select 1 From XX Where Idx = XX.SomeColumn )
Or Exists ( Select 1 From XX Where Idy = XX.SomeColumn )

```

thanx :)