Re: Informal Survey #1 -- joins on foreign keys

On Oct 1, 10:09 am, Rob <rmpsf..._at_gmail.com> wrote:
> First, let me qualify my interests. I am primarily interesested in the
> mechanics of
> relational database management, not the semantics. I am interested in
> the evaluation
> of sql queries without regard to their meaning.
>
> 1. without racking  your brain or searching the archives of your
> previous work, does
> your gut feeling tell you have ever authored or seen an sql query in
> which two relations
> were joined on a foreign key in each?
>
> 2. using your knowledge and understanding of (any) relational algebra,
> is a join
> between two relations on a foreign key in each ever meaningful? (Keep
> in mind
> the definition of the domain of a foreign key.)
>
> 3. in the semantic realm you use to "think about" relational databases
> (i.e., E-R,
> facts, etc.), does a join between two relations on a foreign key in
> each make sense?
>
> I request that you spend at least 10 minutes thinking about this
> before you flame
> me.
>
> Rob

dsads Received on Sat Oct 15 2011 - 12:17:02 CEST