How to ensure specific WHERE condition evaluates first on view

Question

Consider the following view:

create view x as
select 1 as [source],* from some_table
union all
select 2,* from some_other_table

When I run

select * from x where source=1

can I be sure that the select 2.... query is not even executed?

The reason is that in my case, that one is an openquery with sluggish speed, which I want to avoid.

Answer 1

You can do stuff like this, but i dont know if that meets your other requirements you might have - Otherwise you can create 2 views.

CREATE proc dbo.usp_selectspecificquery 

@source int
AS

BEGIN

IF(@source = 1)
BEGIN

Select 1 as source, * from some_table

END
ELSE
Select 1 as source,* from some_table

union all
select 2 as source,* from some_other_table
END

exec dbo.usp_selectspecificquery 1