Re: in-line view

Thanks for your response..

I know the in-line view is resolved first...but does it get executed again and again for every join. or Oracle treat the resolved in-line view as another "table"
ie.
evaluate /do grouping etc etc of in-line view once then do the join the main WHERE clause...

any comments..

"Connor McDonald" <connor_mcdonald_at_yahoo.com> wrote in message news:396314DF.7EE5_at_yahoo.com...
> Cobra__77 wrote:
> >
> > If I use in-lines views....and then join those views later in the where
> > clause...will oracle create the inline view once for each join...or just
> > once for all joins....ie perform the joins and store data for that view
 in
> > memory....
> >
> > eg
> >
> > select a.x, b.y, c.z
> > from (select id,x
> > from tab1
> > where id > 100) a,
> > (select id,y
> > from tab2
> > where id > 1000) b,
> > (select id,z
> > from tab3
> > where id > 30) c
> > where a.id = b.id and a.id = c.id
> >
> > for the above joins will oracle just create 'a' once and store data in
> > memory and then use it for both joins...
> > a.id = b.id and a.id = c.id ...or create 'a' twice ...for both
 joins...to do
> > a.id = b.id and do the other part a.id = c.id ....
> > Please remember that the above example is very simplified....my query is
> > very very complex than the above...and I have tables with more than
 1000000
> > rows...in each in-line views...so determining this will help me a lot in
> > tuning my queries.....
> >
> > any suggestions....
>
> Depends...Oracle can merge various bits and pieces of the SQL and thus
> not need to run them multiple times. Typically if the inline needs to
> be resolved first eg grouping/distinct etc, then you may be out of luck.
>
> HTH
> --
> ===========================================
> Connor McDonald
> http://www.oracledba.co.uk
>
> We are born naked, wet and hungry...then things get worse
Received on Wed Jul 05 2000 - 00:00:00 CDT