Re: U_SUMMARIZE: how aggregate is calculated?

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: Thu, 02 Dec 2004 11:52:48 GMT
Message-ID: <41af01f4.3703453@news.wanadoo.es>

On Wed, 1 Dec 2004 17:59:11 -0800, "Mikito Harakiri" <mikharakiri_at_iahu.com> wrote:

>> >Suppose we have one column relation which is essentially a set of
>intervals:
>> >
>> >{[1,2], [3,5], [4,7]}
>> >
>> >and I want to project away the interval column and calculate aggregated
>> >value of SUM(1). What the result there would be? 3? 2? 7?

>BTW, shouldn't you also
>introduce user-defined aggregate SUM on the intervals?

Yes.

>In my case, however, the column expression is a constant equal to 1, so that
>the SUM has to be a number.

Ok I misunderstood you.

I that case Sum(1) would be equivalent to Count(R) and the result would be 3.

Regards Received on Thu Dec 02 2004 - 05:52:48 CST