Take a look at my comment again, I think you think I'm saying something I didn't. The whole point of that "impedance" in the relational model is to for people

Take a look at my comment again, I think you think I'm saying something I didn't. The whole point of that "impedance" in the relational model is to for people to think about their data and describe it in a program-independent way .... The relational model is hardly the only way to reason about data in a program-independent way. ... years of experience in the field is what led to its development and what contributes to its continued relevance. I agree, never said otherwise. Saying that's a problem with the relational model is like saying that design patterns are flawed because they describe commonly used OO designs. I didn't say there's a problem with the relational model. I'm not sure what sort of impedance mismatch could exist between a program and a relational model ... I never said the word "program," you did. I said "data model." You're conflating the data model with the program code (or maybe you think I am, can't really tell). They are not the same thing. http://en.wikipedia.org/wiki/Abstract_data_type http://en.wikipedia.org/wiki/Abstract_data_type All I said is that there are some domains for which relational models make sense and there are others for which document-oriented (or other "NoSQL") models make sense.