See series starting at
The First Normal Form in Theory and Practice, Part I
Why even the most intelligent software architects don't understand the Relational Model
In 15-20 years from now: Information will stay only in XML (no more tuples, no more objects). Imperative languages as we know them today (Java, C, C++, C#) will be gone. We will program with some extension of XQuery, or in any case a declarative dataflow/workflow language specially --Daniela Florescu, 2010 Interview
Exactly 20 years ago I wrote this article: "Storing and Querying XML Data using an RDMBS". I curse myself every day for doing so. I should be damned by the fires of hell for ever opening my mouth and letting people believe that one can REASONABLY use SQL to query hierarchical, complex structures like XML or JSON. NO, PEOPLE. YOU CAN NOT! --Daniela Florescu, 2015, LinkedIn.com2. To Laugh or Cry?
SQL Will Inevitably Come To NoSQL Databases3. Online Debunkings
Data Scientists: The talent crunch (that isn't)4. Interesting
One would expect “data scientists” to be keen on the dual scientific foundation of database management -- the relational data model (RDM) -- but they know little beyond “related tables” and, in fact, complain that more often than not data “do not fit” into them. Much of that is the result of poor education and an almost exclusive focus on software tool training. Even the analyst intent on acquiring foundation knowledge is more likely to be misled than enlightened by published information.
"... web apps ushered in a new model for development and distributed systems that ... [r]elational databases are fundamentally ill suited to handle ... Their master-slave architectures, methods for writing and reading data, and data distribution mechanisms simply cannot meet the key requirements of modern web, mobile and IoT applications. I tell you that not as an employee of a NoSQL company, but as a guy who has worked with RDBMS’s for over twenty-five years. In short, you simply can’t get there from here where relational technology is concerned, and that’s why NoSQL must be used for the applications we’re talking about.