This OP also said he was a novice, and may not know what exactly is close enough to being the "fastest possible" (and besides, he lists first on his list of priorities "maintainable"). The bottleneck here will be loading the database, and a few extra seconds (if even that) processing the data will probably be insignificant compared to that. That being said, I think Fletch's answer is probably the most straightforward for the problem as stated (and that being said, I'm not even sure I fully understand the problem myself :-)