J M Davitt wrote:
"TRM, on the other hand, would maintain exactly one ordered set of
values for the domain and everything referencing the same date
would refer to the same value. Indices aren't really needed. "
But you still have to store the "everything referencing" stuff,
correct? That's just not going to magically disappear. It seems to me
that all of the advantage comes from having a column store over a
row-store, and that the only way to get less data than a typical
column-store would then be to compress a column with, say, run-length
encoding. In other words, maintaining an ordered set of dates and
having say, five columns referencing that ordered set does nothing for
you over just maintaining five columns of dates if the you use a 32 bit
int for storing the date and 32 bit int for storing the thing that
references the date column. If the column in question were on a wide
character domain then it would save space to have a integer to
reference the column (of just make a new table and have foreign keys
point to the values). So I guess my real question is what does TRM
offer over a conventional column-store, which has been around for well
over 30 years? I've read C.J. Date's small section in the 8th edition
of text book on it, but I don't get it.