>
>Cartesian: Hmmm...
>
>The system of Cartesian coordinates is the most commonly used coordinate system. In two dimensions, this system consists of a pair of lines on a flat surface, or plane, that intersect at right angles. Each of the lines is called an axis and the point at which they intersect is called the origin. The axes are usually drawn horizontally and vertically and are usually referred to as the x and y axes, respectively. In Cartesian coordinates, a point on the plane whose coordinates are (2,3) is 2 units to the right of the y axis and 3 units up from the x axis, as shown in Figure 1. In three-dimensional Cartesian coordinates, the z axis is added so that there are three axes all perpendicular to each other.

I've never been much at math. Getting into geometry is even worse.

>
>Intersting way to describe a runaway group by join. :) Many times I've said to myself, WOW, 3 billion records!!!

Yup, I totally understand. I once worked at a place where I had a 1.7 Gig, 11 million record .DBF. I had to be REALLY careful when joining that with other tables.