Kevin's right of course, try them all, pick the best performing.
Jared
On Tuesday 29 May 2001 13:05, Toepke, Kevin M wrote:
> Jared,
>
> At least with O8i, that's true in about 60-70% of the time. I have found it
> better to use subqueries instead of joins when that's what you mean. In
> some cases the optimizer can eliminate a sort step when using sub-queries
> instead of a join and other times it processes less data.
>
> Sometimes an IN subquery is faster, other times an EXISTS subquery is
> faster. The point is, you have to try the query all 3 ways.
>
> In this case, I suspect that a subquery will be much faster than the join.
> (Because of the rownum = 1 restriction)
>
> Kevin
>
> -----Original Message-----
> Sent: Tuesday, May 29, 2001 3:11 PM
> To: Multiple recipients of list ORACLE-L
>
>
>
> Why change it to subqueries?
>
> The optimizer will just turn it back into a join anyway.
>
> Jared
>
> On Tuesday 29 May 2001 05:15, [EMAIL PROTECTED] wrote:
> > Hallo you DBAs
> >
> > How can I write this sql query using subqueries?
> >
> > SELECT pbk.nielsenart.varunamn, pbk.nielsenart.strl,
> > pbk.nielsenart.varutxt, null, pbk.nielsenart.vgrp,
> > rik2.hierarki_tekst.tekst, null, pbk.sortiment_vgrp.sortiment,
> > pbk.nielsenart.art_grp, pbk.nielsenart.art_ugrp, null FROM
> > pbk.nielsenart,pbk.sortiment_vgrp,rik2.hierarki_tekst, pbk.rapporttmp
>
> WHERE
>
> > pbk.nielsenart.vgrp=rik2.hierarki_tekst.vgrp
> > AND pbk.sortiment_vgrp.vgrp=pbk.nielsenart.vgrp
> > AND rik2.hierarki_tekst.sett_id=2
> > AND rik2.hierarki_tekst.landkode=46
> > AND pbk.nielsenart.ean=pbk.rapporttmp.EAN
> > AND ROWNUM=1
> >
> >
> > Roland Sköldblom
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Author: Jared Still
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