--- In firebird-support@yahoogroups.com, Lee Jenkins <lee@...> wrote:

>
> Adam wrote:
>
> > >
> > > It returned like 18 records that matched the criteria from the
> > 1million +
> > > records in the table so I'd say that was pretty damn fast. I tested
> > in the
> > > application too, where I need to display the user's current sales
> > from today and
> > > it was very, very fast. Coupled with a nice little "Please Wait..."
> > message
> > > that displays for like .5 seconds for subjective speed and I say it
> > looks like
> > > its safe to use one table like I had hoped to do.
> > >
> > > Nice.
> >
> > Great it worked out for you. You may want to also try without the
> > IDX_SALE_SALENUMBER index by changing the last line to.
> >
> > ORDER BY
> > s.SALE_NUMBER+0;
> >
> > Often an indexed sort is slower than an in memory sort.
> >
> > Adam
> >
>
> I'll try that. I'm using an OPF so I'll have to write a hard coded

visitor in

> the morning to do that. In the meantime, does the +0 negate the

index somehow?

Yes.

s.SALE_NUMBER+0 is not an indexed expression, but obviously it is not
going to effect the order. Firebird will not find a plan involving an
ordered walk of the table. It will read the results in the order they
are stored on disk, then sort them in memory.

For 18 records, there is probably not much difference, but it takes
longer for disk platters to jump around to random locations on disk
than it does for arbitrarily ordered data in memory to be sorted.

Adam