inline query vs joins

[henpat123]

Hi,
I have a query like this:
select A.f1, IQ.f1,IQ.f2 from A,
(select id1,f1,f2 from xyz where...) IQ
where
A.id1=IQ.id1
Here we are using a inline view call "IQ".

I can write the same quesry using joins between A and xyz.

My question is: is there any performance difference between the two?

hen_pat

 

[r937]

in theory, no

in practice, maybe

remember, in theory, theory and practice are the same, but in practice, they aren't

does whatever database system you're using offer an EXPLAIN function? that might tell you whether the two approachs are executed the same way

rudy | r937.com | Ask the Expert | Premium SQL Articles
SQL for Database-Driven Web Sites (next course starts May 8 2005)

 

[henpat123]

Ya its ORacle. I 'll try the Explain function!!

Thanks
pat