Also, speed isn't the only thing to consider... If you are ever going to alter the tables or multiple table joins, or try to add full text indexing, or try to do something more complicated, a database will help you. Using a database versus using a (insert language here) script to do what you need to do, is a tradeoff between speed, maintainability, and east of expandibility... If, though, you know
that all you will be ever doing is joining those two tables, and you are ready to deal with the risk of doing the join in the code base, and you need the speed, go for it.