Anand, VJ (MED, GEMS-IT) kirjutas K, 03.12.2003 kell 18:18:
> Hello:
>
> I am trying to find out, how is the B-tree index implemented for
> multiple columns? does Postgres, just
> concatenate the columns ---
Yes.
> if this is the case, then how is the
> search performed? Also, does the optimizer
> choose the index, only when the constraining is on the leading
> subset of the index column?
Yes.
If you want it more complicated, you could check out if PG's R-tree
indexes suit you.
-------------
Hannu