Stored procs can actually improve the separation of business and logic layers, because they help to encapsulate the data layer from the logic layer. You don't

Stored procs can actually improve the separation of business and logic layers, because they help to encapsulate the data layer from the logic layer. You don't want the logic layer to know too much about the internals of the data layer. Stored procs give you a clean, abstracted interface. Also, I wouldn't be too much of a purist about the data/logic distinction. Sometimes doing a little processing on the data in a stored proc before returning it makes sense. On the other hand, I would hesitate to put very complex logic in a stored proc. So as usual, there are going to be grey areas. Do what makes sense.