Re: Finding matching ranges

In article <3b1fc42c.9648133_at_news.gte.net>, JRStern says...
>
>On 07 Jun 2001 16:15:14 +0200, Martin Drautzburg
><drautzburg_at_altavista.net> wrote:
>>I was wondering If I could use a redundant column "g" to speed things
>>up. Ideally I would transform the problem
>> x < given Value < y
>>
>>to something like
>> f1(givenValue) < g(x,y) < f2(givenValue).
>>
>>This would reduce the problem to a simple range scan on the redundant
>>column g(x,y). But I have no idea what functions f1, f2 and g to use
>>(apart from the obvious trivial solution f1=0, g=1, f2=2, which would
>>be logically correct, but would provide absolutely no selectivity).
>
>
>You're probably best off letting the computer earn its keep. Buy some
>more RAM if you must. End of problem, for the most part.

You are kidding right? If I ask you how to find a person by name, case ignored, what index should I introduce, would your ahswer still be "to buy more RAM":-?

As far as the original question is conserned, assuming that your problem has an indexing solution, it would be also applicable to spatial/temporary domain. The fact that spatial doesn't have widely recognised indexing mechanism (compared to B-tree) sound like an indicator that your problem is hard. Received on Sat Jul 21 2001 - 18:30:57 CDT