These are intriguing comments but there is more to it than one versus two versus three layers. FileMaker is great for rapid development. When you start adding layers I cannot see why this is any better than developing your tool in another platform where the database and code are naturally seperate. SQL upgrades to the table structure are done without affecting the data and compiled code is upgraded without affecting the data at all, too. Clean and simple. So, it seems to me that the only reason to do the three table thing is really that FileMaker is your safety zone. Not that I feel real comfortable with MySQL and Java, yet. But that seems to be the more logical way to develop a commercial tool. Are there advantages to FileMaker compared to more traditional development platforms other than it is my comfort zone?