Re: What to call this operator?

Mikito Harakiri wrote:
> As Jon correctly noticed, I goofed with outer union:-)
>
> Marshall Spight wrote:
>

>> ...

>>My intuition is that there might be some advantage to
>>building systems with as few primitives as possible
>>because it would simplify the optimizer. But that's
>>not immediately clear.

D&D chapter 4 intrigues me for a similar reason - it seems more directly programmable suggesting a more elemental (and i would hope, smaller) implementation without the confusion that i think the sql products have produced with their attention to user artifacts such as files and 'tables' which seem to have led to all kinds of detours and dead ends over the last 30 years. just my intuition too.

i don't know enough theory to talk much about optimization, but the optimizations that would intrigue me would be ones that let results, intermediate or 'final' be expressed as multiple relations. maybe my ignorance is also showing when i say that i wouldn't mind having to operate on a negated table.

the place of <OR> in the world puzzles me too. for one thing it appears to me that it produces the same result of <AND> when there are no attributes in common, ie. cartesian product. am i wrong?

if it does product the cartesian product, is this somehow contrary to orthogonality?

so far, the only use i can see for <OR> is as a separate version to double-check the results of <AND> and <NOT>. or maybe as an optimization on occasion.

p Received on Tue Jun 28 2005 - 22:12:55 CEST