>I think that's the wrong approach. As you've said, you'll use the minimum capabilities of each, but you won't get any of the benefits out of any of them. You should pick one database server and learn how to use it well, and taking advantage of its benefits.

You are completely right.

If I develop an specific app to a specific client, that uses in his/her company a specific SQL software, I can use all of that engine's capabilities, which is good, but if develop an app that can be used by diferent clients, and each of them uses diferent SQL software, think that's the aproach I should use, otherwise won't be able to sell the product to clients that use other SQL software than that I used (in its full capabilities) to develop the app. Think that's the price I have to pay.

The point is: people (at least here in Brazil) don't want to hear that an application is developed using DBFs, but if It is a Client/Server app (using SQL Server, Oracle, MySQL etc) they "tend" to change their mind (even if the front end is a VFP app).