Re: Hashing for DISTINCT or GROUP BY in SQL
Date: Tue, 12 Oct 2010 13:28:54 -0700 (PDT)
Message-ID: <d3cdc083-2665-4d84-a1d4-fcf774e3cdcf_at_i5g2000yqe.googlegroups.com>
On 12 oct, 19:44, Erwin <e.sm..._at_myonline.be> wrote:
> On 12 okt, 18:35, -CELKO- <jcelko..._at_earthlink.net> wrote:
>
> > Does there exist a set of hashing functions, H1(), H2(), .., Hn()
> > which will produce at least one different result for any pair of data
> > values?
>
> If you can explain to me how a _SET_ (of hashing functions) can
> "PRODUCE" a result, then I might consider trying to think about this.
Since the above SQL-hack attempt fundamentally ignores the necessity
for the sub system onto providing effectiveness in constraint
specialization and header definitions runtime implementations, it
remains nothing else than a dead end revisitation of OBJECTID.
The theory of *key-reduction* (for a lack of a better word) as whole is simply a waste of time. Received on Tue Oct 12 2010 - 22:28:54 CEST