Hi,
Don’t forget that you can have indexed fields that search quickly that are NOT primary keys.
A good example is my own tipsters database where the PRIMARY key is actually a quite useless field that simply has the tip id.
BUt I have indexed fields for home side, away side, competition, match date and tipster … which allows me to pull out all sorts of lists.
It sounds like neither key field that you mentioned actually need to be primary keys at all – in fact you could adopt the same method I have above and just give each record an arbitary “slot number”.
(or have I gone way off base here?)