Re: Modeling General Graphs in SQL

Marshall Spight wrote:
> mikharakiri_nospaum_at_yahoo.com wrote:
> >
> > The minimum path query is the same as transitive closure, which is
> > widely believed to be inexpresible by standard SQL.
>
> I was under the impression that it was proven, rather than "widely
> believed." Am I mistaken? Is this one of those things that's not
> been proven one way or the other?

You are correct. It has been proven that transitive closure is not possible in SQL. There are ACM papers and others. If you google for

sql transitive-closure

there are many relevant resources, some with a proof and others which introduce possible extensions to SQL for transitive closure. --dawn Received on Wed Dec 28 2005 - 16:47:17 CET