WL#3004: RTREE for non-OpenGIS data types

From JD on 12/6/2005:

In fact, for that one, the best thing might have been to have R-Tree
indexes -without- OpenGIS.

Whenever you run queries like "WHERE col1 BETWEEN (a and b) AND
col2 BETWEEN (x and y)" it would be nice to have an R-Tree index
on (col1,col2).