Showing posts with label CCL. Show all posts
Showing posts with label CCL. Show all posts
Friday, March 19, 2021

Data Sublanguages vs. Programming Languages

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Revised 3/20/21 I recently came across a review of Edsger Dijkstra's work, where the following comment on a book he co-authored (referr...
Saturday, October 17, 2020

Understanding Codd's 12 Rules for RDBMS

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In response to an online publication of a book appendix regurgitating Codd's 12 famous rules (some of which were, typically, incorrect[ ...
Wednesday, January 22, 2020

TYFK: Why is a relational database so powerful?

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  Note: About TYFK posts (Test Your Foundation Knowledge) see the post insert below. “...the theoretical awesomeness of relational algeb...
Friday, November 1, 2019

Comments on a Stonebraker Article

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These comments were prompted by a LinkedIn post referencing Michael Stonebraker's Those Who Forget the Past Are Doomed to Repeat It   -...
Saturday, October 26, 2019

Data Sublanguage Part 4: Conclusion

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In Parts 1 , 2 , and 3   we showed that when the RDM is the data model: A data sublanguage is short for data manipulation language (DML) ...
Friday, September 27, 2019

Data Sublanguage Part 2: Data Manipulation and Definition

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Revised 10/10/2019. In Part 1 we showed that Codd intended in 1969 to base the RDM on axiomatic set theory (AST) and second order logic ...
Sunday, September 22, 2019

Data Sublanguage Part 1: Relational vs. Computational Completeness

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Note: I have revised the "Logical Access, Data Sublanguage, Kinds of Relations, Database Redundancy, and Consistency" paper in th...
Sunday, April 28, 2019

Understanding Data Modeling Part 3: OO/UML, and "Graph Data Models"

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In Part 1 we presented some foundation knowledge with which to debunk misconceptions lurking in the industry's "data modeling...
Wednesday, March 27, 2019

Graph Databases: They Who Forget the Past...

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Out of the plethora of misconceptions common in the industry[ 1 ], quite a few are squeezed into this paragraph: “The relational database...
Saturday, February 16, 2019

Class, Type, Set, Relvar, and Relation

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Note: This is a rewrite of a part of an older post (now redirecting here), to bring into line with McGoveran's formalization, re-inter...
Sunday, February 10, 2019

Understanding Domains and Attributes

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Note: This is a rewrite of one section of an older post (page thereof now links here), to bring it into line with McGoveran's formaliz...
Saturday, March 24, 2018

Data Modeling and NoSQL

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Revised 3/25/18 "To the question “How relevant is data modeling in the world of NoSQL?” I give the following answer. The main pur...
7 comments:
Monday, March 5, 2018

Physical Independence Part 1: Don't Mix Model with Implementation

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Note: This is a rewrite of several older posts (which now link here), to bring them into line with the McGoveran formalization and interpr...
Sunday, December 10, 2017

Conventional Wisdom and True Relational Features

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Here's what's wrong with last week's picture, namely: "Per Date’s AN INTRODUCTION TO DATABASE SYSTEMS, Date & Darwen’...
6 comments:
Sunday, August 27, 2017

Object Orientation, Relational Database Design, Logical Validity and Semantic Correctness

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Note: This is a 8/24/17 rewrite of a 5/20/13 post to bring it in line with McGoveran's formal exposition of Codd's RDM [1] and it...
2 comments:
Monday, July 3, 2017

New Paper: Logical Symmetric Access, Data Sub-language, Kinds of Relations, Database Redundancy and Consistency

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Pls see the PAPERS page for the current version of this paper, when it becomes available.
Sunday, September 20, 2015

Re-Write

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Understanding Codd's 12 Rules for RDBMS