Index Usage

It seems I've searched for years on this one, on and off, but haven't ever found an acceptable answer. I have a table x with a single composite index created on columns a, b, c (in that order). I'm interested to know HOW MUCH of the composite index a particular query is using - is it using column a in the index, columns a and b, or all three parts of the composition?

rjh Received on Fri Jun 17 2005 - 16:49:00 CDT