There are a number of different ways this problem can be solved, but they each have costs: programming time, storage space, etc.. To help the people trying to give you an answer suited to your application, can you tell us (A) How many rows you have in MyTable ? Is it more like thousands or millions or billions ? (B) Is it important in your app that answers can be returned in less than a second, or is a delay of a couple of seconds acceptable, or is a longer delay acceptable ?