A co-Relational Model of Data for Large Shared Data Banks by Erik Meijer and Gavin Bierman.
I missed this when it appeared in March of 2011.
From the conclusion:
The nascent noSQL market is extremely fragmented, with many competing vendors and technologies. Programming, deploying, and managing noSQL solutions requires specialized and low-level knowledge that does not easily carry over from one vendor’s product to another.
A necessary condition for the network effect to take off in the noSQL database market is the availability of a common abstract mathematical data model and an associated query language for noSQL that removes product differentiation at the logical level and instead shifts competition to the physical and operational level. The availability of such a common mathematical underpinning of all major noSQL databases can provide enough critical mass to convince businesses, developers, educational institutions, etc. to invest in noSQL.
In this article we developed a mathematical data model for the most common form of noSQL—namely, key-value stores as the mathematical dual of SQL’s foreign-/primary-key stores. Because of this deep and beautiful connection, we propose changing the name of noSQL to coSQL. Moreover, we show that monads and monad comprehensions (i.e., LINQ) provide a common query mechanism for both SQL and coSQL and that many of the strengths and weaknesses of SQL and coSQL naturally follow from the mathematics.
The ACM Digital Library reports only 3 citations, which is unfortunate for such an interesting proposal.
I have heard about key/value pairs somewhere else. I will have to think about that and get back to you. (Hint for the uninitiated, try the Topic Maps Reference Model (TMRM). A new draft of the TMRM is due to appear in a week or so.)