• First Normal Form (1NF) in Theory and Practice, Part 1
• First Normal Form (1NF) in Theory and Practice, Part 2
• First Normal Form (1NF) in Theory and Practice, Part 3

09/19/23: For the latest on this subject see: FIRST NORMAL FORM - A DEFINITIVE GUIDE

Note: This is a 11/23/17 revision of Part 3 of a three-part series that replaced all of my previous posts on the subject (pages of which redirect here), in order to further tighten integration with the formalization and interpretation [1] of McGoveran's formalization and interpretation [1] of Codd's true RDM.

(Continued from Part 2)

 
"Is this table in 1NF?" is a common question in database practice. On the other hand, "What problems are solved by splitting street addresses into individual columns?", or  What's the best way to store an array in a relational database does not seem to evoke associations with 1NF. This reveals poor foundation knowledge.

Part 1 introduced the poor understanding of 1NF and Part 2 provided a correct definition and explanation. Part 3 explains how 1NF can be enforced by the data sublanguage, which SQL does not.

1. What's wrong with this picture?

NoSQL database management systems give us the opportunity to store our data according to more than one data storage model, but our entity-relationship data modeling notations are stuck in SQL land. Is there any need to model schema-less databases, and is it even possible? --Theodore Hills, The Hybrid Data Model, Dataversity.net

09/19/23: For the latest on this subject see: FIRST NORMAL FORM - A DEFINITIVE GUIDE

Note: This is a 11/23/17 revision of Part 2 of a three-part series that replaced all of my previous posts on the subject (pages of which redirect here), in order to further tighten integration with the McGoveran formalization and interpretation [1] of Codd's true RDM.
(Cont'd from Part 1)
 
Part 1 raised the issue of poor understanding of Codd's concept of a simple domain with atomic values underlying 1NF. In Part 2 I clarify Codd's definition of 1NF and its correct interpretation.