On Sun, 2006-08-20 at 19:59 +1000, chris smith wrote:
> On 8/20/06, Ow Mun Heng <[EMAIL PROTECTED]> wrote:
> > I'm have a query like so
> >
> > select
> > A,
> > index_A
> > from
> > tableA
> > join tableB
> > on tableB.indexA = tableA.indexA
> >
> >
> > select
> > A,
> > index_A
> > from
> > tableA
> > join tableB
> > on tableB.A = tableA.A
> >
> > whcih would be more efficient? using the where clause which uses the
> > index or the one which isn't index?
> 
> If you join using the field that is indexed, this will use an index.
> 
> If you join using the field that isn't indexed, it can't use an index.

I take it that that means yes, it's more efficient performance wise to
always use an index.

Thanks.


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