If one decides to use a composite key, beyond how many attributes should one seriously consider creating a surrogate key instead? 4? 5? Less? I have seen a composite key composed of 5 attributes and thought - why? What's the value over a surrogate key? I guess choosing a candidate key (presuming the candidates are legitimate candidates) is at least partially a matter of taste. What taste would compel people to choose composite keys composed of more than 2-3 attributes?
