Content deleted Content added
m Dating maintenance tags: {{Confusing section}} {{Page needed}} {{Pages needed}} {{Clarify}} |
Changed the header to be more descriptive of the content |
||
Line 129:
* 1NF has been interpreted as not allowing complex data types for values. This is open to interpretation though, and [[Christopher J. Date]] has argued that values can be arbitrarily complex objects.{{citation-needed|date=June 2023}}
== Controversy about atomic values ==
[[Hugh Darwen]] and [[Christopher J. Date]] have suggested that Codd's concept of an "atomic value" is ambiguous, and that this ambiguity has led to widespread confusion about how 1NF should be understood.<ref>Darwen, Hugh. "Relation-Valued Attributes; or, Will the Real First Normal Form Please Stand Up?", in C. J. Date and Hugh Darwen, ''Relational Database Writings 1989-1991'' (Addison-Wesley, 1992).</ref><ref>{{cite book |last=Date |first=C. J. |author-link=Christopher J. Date |chapter=Chapter 8: What First Normal Form Really Means |date=2007 |title=Date on Database: Writings 2000–2006 |publisher=Apress |isbn=978-1-4842-2029-0 |page=108 |quote='[F]or many years,' writes Date, 'I was as confused as anyone else. What's worse, I did my best (worst?) to spread that confusion through my writings, seminars, and other presentations.'}}</ref> In particular, the notion of a "value that cannot be decomposed" is problematic, as it would seem to imply that few, if any, data types are atomic:
*A [[String (computer science)|character string]] would seem not to be atomic, as an RDBMS typically provides operators to decompose it into substrings.
| |||