> Sure, as soon as you access a database that wasn't designed for the ORM you run into trouble Don't you mean the reverse? A relational database is never desig

> Sure, as soon as you access a database that wasn't designed for the ORM you run into trouble Don't you mean the reverse? A relational database is never designed "for the ORM" -- ORMs are designed (sometimes poorly, sometimes better) for some databases. The object-relational impedance mismatch problem is well known in software engineering for a reason: OOP and relational databases weren't designed with each other in mind, and in fact, "fight against each other" in many ways. This is the starting point of the Vietnam article -- you can disagree with the analogy, but the impedance mismatch is very real.