> The concept of sets and order may not be mutually exclusive in the mathematical theory but in terms of how actual databases were conceived and implemented the

> The concept of sets and order may not be mutually exclusive in the mathematical theory but in terms of how actual databases were conceived and implemented they were very far apart. I may be wrong, but it was my understanding the original Relational Databases were very much based on the Relational Algebra originally pioneered by E.F. Codd[1]. So I think it is a stretch to say that they were "conceived" separate from the mathematics. Further, it was my understanding that E.F. Codd took his relational algebra which he developed while working as a researcher at IBM and applied it to an implementation of an RDBMS also at IBM (now known as IBM DB2)[2]. So similarly, I think it is a stretch to claim that databases were originally implemented "far apart" from the mathematics. I think there is a valid point that actual DB implementations may be lacking, but isn't that a reason not to use that particular implementation rather than a knock against Relational models? I may be wrong, but it seems like your problems aren't with the Relational Model but rather with potentially lacking/incomplete implementations of it. [1] https://en.wikipedia.org/wiki/Relational_database https://en.wikipedia.org/wiki/Relational_database [2] https://en.wikipedia.org/wiki/IBM_DB2 https://en.wikipedia.org/wiki/IBM_DB2