>
> >From X3H2-97-030 (I think)
> c) Let P be any row of TS and let Q be any other row of TS,
> and let PVi and QVi be the values of Ki in these rows,
> respectively. The relative position of rows P and Q in the
> result is determined by comparing PVi and QVi according to
> the rules of Subclause 8.2, "<comparison predicate>", where
> the <comp op> is the applicable <comp op> for Ki, with the
> following special treatment of null values. Whether a sort
> key value that is null is considered greater or less than
> a non-null value is implementation-defined, but all sort
> key values that are null shall either be considered greater
> than all non-null values or be considered less than all non-
> null values. PVi is said to precede QVi if the value of the
> <comparison predicate> "PVi <comp op> QVi" is true for the
> applicable <comp op>.
> And if anyone can follow that.......
> Adrian
>
Basically, it means that NULLs are always to be treated as greater or
less than any non-NULL value. Which of these it is is up to the
programmer/designer, but it must be consistant. Otherwise stated,
regardless of NULLs, a set of records should always sort in the same
relative order, ascending or descending.
(Gee, that ALMOST made more sense than the standard text... *sigh*)
- -Brandon :)
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