Re: no names allowed, we serve types only
Date: Wed, 17 Feb 2010 22:08:55 -0800 (PST)
On Feb 17, 7:21 pm, Tegiri Nenashi <tegirinena..._at_gmail.com> wrote:
> On Feb 17, 3:46 pm, Tegiri Nenashi <tegirinena..._at_gmail.com> wrote:
> > The thread started as Keith's attempt to demote attribute names in
> > favor of types,
Eliminate not just demote.
> > and was vehemently objected to. From my angle (that
> > would be relational lattice:-) Relational Model is a theory of
> > Relations with Named Attributes. It is difficult to see unnamed
> > perspective (with positional attributes) as contender anymore. This is
> > especially evident through the prism of set intersection join (aka
> > composition) operation...
Except that I'm not proposing "positional attributes" so I fail to see the relevance of your point? First, I'm asking a simple question: suppose we have already have unique types for every header then what theoretical capability do the names add? (Bob argues that they are necessary for "controlling" natural join. I disagree that they are /necessary/ for this; but my complete response to that will have to wait a few days.)
Second, I'm pointing out that if the answer to that question is "none", then a set of unique types is sufficient to logically identify attributes and names are not needed. Third, operating on types for such things as "rename" etc is really not any more difficult than for attribute names (given the proper tools).
> Let me clarify these ideas. In unnamed perspective attributes are
> numbers indicating _relative_ position of each attribute in each
> individual relation. One have to devise some drudgery conventions to
Not in what I'm proposing. There is no "positional" anything. Instead I simply claim, you need either unique names or unique types. You do not need both. Having unique names instead of unique types MIGHT BE convenient especially giving the paucity of domain support these days, but it is not, in principle, necessary.
Your "positional" points seem like a distraction or red herring.
KHD Received on Thu Feb 18 2010 - 07:08:55 CET