Keep table joins to 2!!??

Sorry, but that's just silly, as it is pretty much impossible and wholly un-necessary.

Now, I will say that the more tables you join, the longer your statement will take. However, while that is true, that is an *extremely* short-sighted view of performance. There are many, many factors to be considered when designing a database, and many, many variables that affect performance. The simple rules to remember are that 1)an OLTP database should be fully normalized. Then, 2) you can *add* some targetted de-normalized fields for performance. As for lookups, 3) each should have its own tables for multiple reasons. The most important are RI, flexibility and performance. Looking through 3000 states and provinces and countires and cities just to find Male or Female entries is not optimal. There are some more base assumptions, but they are off-topic here. Given these base assumptions, it is true that you will end up with multiple tables in most of your SQL. The goal then is to learn how to optimize such access. There are many tricks to doing that. If you break any of the base assumptions, however, you will find yourself quickly facing more, larger issues which are not so easily solved.

My .02,

- Chris