Re: How to search date ranges

Absolutely BRILLIANT !!! A tip like that is what I was hoping for, though it appears from Sybrand's letter, I have a lot to learn about tuning SQL.

Many thanks !!
I can't wait to get to work to try it.

"Jaap W. van Dijk" <j.w.vandijk_at_hetnet.nl> wrote in message news:3c547f4f.2248076_at_news.freeler.nl...
> Apart from the problem you are having with your query optimization, if
> you have two intervals a to b and p to q and you want to check for
> overlap it suffices to check the following condition:
>
> b >= p and a <= q
>
> Assuming that equal values constitute an overlap. If this condition is
> true, you have overlap, if it's not true you don't have overlap.
>
> Check it out for your examples.
>
> Jaap.
>
> On Sun, 27 Jan 2002 17:52:30 GMT, Michael Gill <mydba_at_usa.com> wrote:
>
> snip
> >
> >
> > O-----------------O
> > start stop
> > O------O
> > O---------O
> > O---------O
> > O-------------------------------O
> >
> snip
> >
> > SELECT Count(s.Person_ID)
> > FROM SCHEDULED s, Event e
> > WHERE ((e.Start_Time > (TO_DATE('14-nov_01')) AND (e.Start_Time <
> >TO_DATE('15-nov_01'))) OR
> > (e.Stop_Time > (TO_DATE('14-nov_01')) AND (e.Start_Time <
> >TO_DATE('15-nov_01'))) OR
> > ((e.Start_Time <= TO_DATE('14-nov_01')) AND (e.Stop_Time >=
> >TO_DATE('15-nov_01')))) AND
> > (e.Event_ID = s.Event_ID) AND
> > (s.Person_ID = 9957)
> >
> snip
>
Received on Sun Jan 27 2002 - 21:39:36 CST