Re: What is general term for this problem?

On Thu, 16 Sep 2004 12:34:23 -0400, Kenneth Downs wrote:

>The reason this cannot be solved without a loop is that the JOIN between one
>supply row and one demand row actually results in a WRITE to both rows,
>which affects the next JOIN you do. Therefore you must evaluate row by
>row.

Hi Kenneth,

Not necessarily. This kind of problems can often be tackled with a subquery to calculate a running total.

>I have little hope that there is actually a set-based solution, but if I
>have missed something and there is, that would be good news.

Your description is not complete enough to tell for sure, but there might be a set-based solution. It would require several running-total-type subqueries; the whole would probably become rather ugly and it might perform even worse than a cursor-based approach, but if you're determined to do it set-based, it might be possible.

Best, Hugo

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