Re: Principle of Orthogonal Design

Jan Hidders wrote:
> mAsterdam wrote something very much like:
>> Pragmatical redefinitions must be temporary and tracked.
> Sure, we agree on that.

<unsnip>

Wether the relation between heading and tuples goes via names or ordering is relevant or not.

If it is not I want it out of scope.

</unsnip>

>> DEFINITION: Two relations R and S are said to have dependency-induced
>> overlap if there is a dependency that requires that sometimes some
>> tuples(1) of R are also in S.
>>
>> (1) for some definition of tuples that allows restricted
>> reshuffling of its values. To do.

Nice, a third alternative way to state the same relation. How can this be relevant?

> Such an operation on its internal organs is going
> to change the relational model beyond recognition.

This is hardly surprising when part of the (database local) definition of relation is under discussion. More specifically: How do tuples conform to relation headers?

> I'm going to
> strongly insist that we stick to the classical definitions of the
> named perspective and state in the definition that we are talking
> about inclusion up to relabeling:
>
> DEFINITION: Two relations R and S are said to have dependency-induced
> overlap if there is a dependency that requires that sometimes some
> tuples of R are also in S after renaming the attribute names.

Two glossary todo items: [Trivial](new) and [Type]. The s/meaning overlap/dependency induced overlap/ did help to clarify.

This time 'type' is the label on a jar containing something else. Which 'classical definitions of the named perspective' do you mean?

Do you have a suggestion for
s/type/$some_name_dependent_notion_similar_to_but_not_the_same_as_type/ in PoOD related discussions ? Received on Mon Jan 28 2008 - 02:12:17 CET