Back to the roots, Relational Data Model

Some thoughts on how or why to compare Relational data model with other data models

Table of Contents

Back to the roots

Recently, I realized that the associative, semiotic, hypergraph, or in short the R3DM/S3DM, technology framework we propose to be adopted in database management systems can be considered in many ways an extension to Codd’s Relational Model. I am aware that this is a big claim and certainly this is not the place or the time to lay down my arguments, suffice it to say how this occurred to me.

I have partially implemented TRIADB technology twice on top of two different data stores and I noticed that those add and get operations we defined are closely related to Codd’s relational algebra operations, while data sets, i.e. domains, and a user defined type system match the sets defined in mathematics and relational theory. Coincidentally Codd’s Relational logic goes back to Aristotle and the corner stone of our technology, which is the computational semiotic triangle, goes back to Aristotle too. I will briefly mention that one basic difference is that both the heading set and the body tuples of the Relation, in fact everything, are transformed and uniformly represented with numerical key references. Therefore it can also be called Reference Database Management System (RDBMS). All these are simply good indications. I believe we are on the right track.

The truth is, and I will quote Chris Date here, that:

if you are proposing to replace technology A by technology B first is counted on you to understand technology A and then it is counted on you that there is some problem that technology A does not solve and technology B does solve 1

And the best person I have found to teach me Relational database technology, so that I can acquire an in-depth understanding, is Chris Date himself. The following video is a clip from an excellent, illuminating workshop that explains Codd’s Relational Theory to computer professionals, but most importantly, he shows what a real relational product would be like, and how and why it would be so much better than what’s currently available.

Relational model vs Other data models

That said, allow me to have my doubts about whether many of the proponents of other database technologies, including those in SQL databases and those in NoSQL databases, have understood what are really the differences with respect to Relational model and at what abstraction level they occur. Again this is not the place or time to elaborate on this. Instead, I am inviting you to ponder on the architectural design of modern database management systems.

You see in practice, it is too difficult to make a very clean separation between the physical, logical and conceptual levels of information. From an engineer’s point of view it is hard to separate theoretical from practical purposes. Moreover, many of these NoSQL DBMS, that are in fashion nowadays, are suited to solve a particular type of problem and this is why you often hear that big corporations and large companies have many different kinds of DBMS at the back-end. Not to mention that nowadays there is the trend to market many DBMS as multi-model database systems. And that made me also to realize that:

there has to be a distinction between those problems that one solves at the physical level e.g. physical layout, partition and availability and those that apply more at the logical-conceptual level e.g. integrity and data modeling. Therefore, I foresee that in the future systems will have to use a combination of these two levels that somehow will have to be tuned and made to work harmonically independent of each other2

Our perspective

This is our perspective towards the architectural design of modern database management systems that fully justifies our choice of marketing TRIADB as a middleware. We are focusing to provide an efficient and effective solution at the logical and conceptual level using an existing implementation of the database physical layer. Relational modeling theory applies here too, from what I understand it was the implementation details at the physical level and perhaps other naive simplifications that made many to depart from the original Relational model. So it’s time to return back to the roots and make some real progress.

In case you, as a reader, have the same feelings and see some truth on my writing, I would be more than happy to discuss with you about the progress we are making with TRIADB and associative, semiotic, hypergraph technology and definitely exchange ideas and share some common thoughts on these database topics. Stay tuned.


  1. Chris Date - SQL and Relational Theory Master Class - O’Reilly Workshop ↩︎

  2. Athanassios I. Hatzis, LinkedIn post, March 2018 ↩︎

Athanassios I. Hatzis, PhD
Software Engineer - Researcher, Founder/Independent Contractor