Re: A new proof of the superiority of set oriented approaches: numerical/time serie linear interpolation

On May 1, 12:26 am, Cimode <cim..._at_hotmail.com> wrote:
> My belief (and hope) would be that using interpolation
> could represent a method more *systematic* (and therefore more easy to
> program in a dbms) to handle missing information.

One more observation. Interpolation, regression

http://en.wikipedia.org/wiki/Regression_analysis

, prediction, and tons of other stuff from infamous AI arena are all technically a join. Consider a "learning" set

X Y

and a set of unknown values

X

--
4
5
7

for which the system is requiered to predict the Y values. "Obviously"
the answer in this rather unsophisticated example is

X   Y
-----
1   1
2   4
3   9
4   16
5   25
7   49

The left outer join between the learning set and the set of unknowns
is the mother of all prediction methods that just guesses all the
unknown Y values to the NULLs:

X   Y
-----
1   1
2   4
3   9
4   NULL
5   NULL
7   NULL

Therefore, prediction operation is technically some sort of a join.