In what order does execution on WHERE and ON clauses work?

Question

I was reading this page about APPLY:

http://sqlblog.com/blogs/alexander_kuznetsov/archive/2009/07/07/using-cross-apply-to-optimize-joins-on-between-conditions.aspx

Answer 1

They are not the same queries so why would you expect the same response times

If the two queries are returning a different number of rows then use a top X for a more fair comparison

Query optimizer can get very smart (and it can get stupid)
View the query plan to see what is going on

My experience is the query optimize has a better chance of getting smart if you pull the conditions into the join

SELECT s.StartedAt, s.EndedAt, c.AirTime 
 FROM dbo.Commercials s 
 JOIN dbo.Calls c  
   ON c.AirTime >= s.StartedAt 
  AND c.AirTime < s.EndedAt 
  AND c.AirTime BETWEEN '20080701' AND '20080701 03:00' 
  AND s.StartedAt BETWEEN '20080630 23:45' AND '20080701 03:00'

If you just have a single join then the query optimizer may move a where early
But if you have multiple joins I have never seen the query optimizer move a where early