Re: header part of the value?

On Feb 29, 6:49 am, Marshall <marshall.spi...@xxxxxxxxx> wrote:
On Feb 29, 1:23 am, Jan Hidders <hidd...@xxxxxxxxx> wrote:

Certainly in practice this is the sort of thing that would
be almost universally a good idea. But what theoretical
basis does it have?

Static typing goes out the window.

Yes, certainly; that bears mentioning. That doesn't change the
algebra at all, though, does it?

The standard relational algebra is essentially statically typed and
it's formal definition is based on that. If you drop that, you will
have to give new definitions that take into account that the headers
might not be what you expect. I would not call that "doesn't change at
all".

I suppose that's true.

Hmm, I don't think I said this strongly enough. What I meant to
say was, "Aha, it appears that you are right and I was wrong."


It is not true of the relational lattice though.


Marshall
.