Re: TRM - Morbidity has set in, or not?

J M Davitt wrote:
> Marshall Spight wrote:
> >>
> >>It *is* much more that a column store storage scheme. I don't know
> >>whether you've read a description of TRM, but it features (a) a
> >>not-so-surprising ordered collection of observed values, (b) a mildly
> >>clever permutation and inverse permutation index, and (c) a very clever
> >>"record reconstruction table."
> >
> > Your paragraph above seems to me to be a pretty good description
> > of a column store with a fully inverted index. My understanding
> > is that these techniques are decades old.
>
> Like the "inverted hierarchy?" Yes, that is old enough to be well
> known. The TRM difference is that a value in a column appears
> exactly once -- no matter ho many times it appears in the
> representation. A further point not made is that each value need
> appear only once in a domain.

In an inverted index, the value appears exactly once.

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

Marshall Received on Sun May 14 2006 - 00:05:27 CEST