Re: Limits

On Jul 26, 1:17 am, Tegiri Nenashi <TegiriNena...@xxxxxxxxx> wrote:
On Jul 25, 2:58 pm, JOG <j...@xxxxxxxxxxxxx> wrote:

For instance if we have relation:
R := {w, x, y}

where the tuples are:
w := (a:1, b:1)
x := (a:2, b:2)
y := (a:3, b:2)

then "ordering by a" yields a total ordering over R:
{(w, x), (w,y), (x,y)}

but "ordering by b" gives the partial ordering:
{(w, x), (w,y)}

OK. But who the recepient of the ORDER BY output? I assume it is some
sort of SQL client. Can it understand partial order?

No, of course not, because clients tend to allocate tuples into an an
array, and certainly don't store them as a set even logically.
However, this is somewhat of a digression, because I was concerned
with the theory - whether such concepts can be integrated into RA, and
if doing so offers any utility. Ordering seems important.
.