Follow @DBDebunk Follow @ThePostWest

1. Quote of the Week

To clarify my point further, although M doesn't care about how it's implemented, the implementation has a strong influence on the logical structures that it's trying to implement. In a normalized or demoralized [sic] debate, a fully normalized physical schema is always good, when implemented on an infinite performance hardware. --LinkedIn.com

2. To Laugh or Cry?
I recently attended a presentation on Azure DocumentDB, Microsoft's NoSQL cloud product. I made the following notes:

• Polyglot persistence: Wasn't this what the RDM was supposed to substitute? 
• Hierarchy: Didn't we get rid of HDM decades ago?
• NoSQL: No SQL, but a "SQL-like" language (it's barely relational and now it's used for documents?)
• No integrity, data independence: Nothing learned from the past.
• Cloud: At least mainframes were under each company's control.

Progress.

3. Online Debunkings

Comments on "Michael Stonebraker Explains Oracle’s Obsolescence, Facebook’s Enormous Challenge"

4. Interesting Elsewhere

Unskilled and Unaware of It

5. And now for something completely different

Follow @DBDebunk Follow @ThePostWest

My April post @All Analytics.

Aside from domain constraints, every R-table designed to represent a single class of entities is also subject to table constraints that approximate in the database class business rules in the real world. If the rules are not documented, for the conscientious analyst who wants to guarantee sensible data manipulation and result interpretation they are the next best thing.

Read it All. (Please comment there, not here)



 

Follow @DBDebunk Follow @ThePostWest

DBDebunk readers should know of David McGoveran (see his bibliography under FUNDAMENTALS), whose work on relational theory and practice has appeared or been discussed on the old site and here over the years. On more than one occasion I mentioned the Principle of Orthogonal Design (POOD) identified by David, who had published several years ago work he did on the subject with Chris Date. The POOD has relevance to updating relations and particularly views and led to Date's VIEW UPDATING AND RELATIONAL THEORY book .

I recently mentioned that David's and Date's understandings on POOD have diverged since their joint effort--currently Date and Darwen reject the POOD as formulated then and David has problems with Date's understanding of it and with their THE THIRD MANIFESTO (TTM) book.

David is working on a book tentatively titled LOGIC FOR SERIOUS DATABASE FOLKS where he will detail his views on RDM in general and POOD and view updating in particular, but in the meantime I asked him to publish an early draft of a chapter on the latter subject, which he did-- Can All Relations Be Updated?--and which he has just revised.

He has asked me to post a clarification on the nature of the differences with Date and Darwen (see next) and I used the opportunity to interview him about his impressive career, which covers much more than database management. David provided written answers to questions.

Follow @DBDebunk Follow @ThePostWest

1. Quote of the Week

Hopefully with the emergence of better cloud infrastructure and unstructured databases, it'll become easier and easier to build utilities to handle the intake and transformation of big, messy datasets into units of info ready for insights. SocialScale (socialscale.io) just launched an MVP a month ago to provide instant access to raw social data (via Gnip), ready-for-analysis, in any tool. --LinkedIn.com

2. To Laugh or Cry?

Are SQL Relational DBMS's Here to Stay?

3. Online Debunkings

• Comments on Integrity constraints as approximations to business rules
• Comments on First Normal Form, Part 1 Atomicity

4. Interesting Elsewhere

• Lies, Damn Lies And The Myth Of Following The Data
• What Does Big Data Mean: A Cynic's Guide

5. And now for something completely different

Follow @DBDebunk Follow @ThePostWest

See series starting at

The First Normal Form in Theory and Practice Part I

Follow @DBDebunk Follow @ThePostWest

1. Quote of the Week

I'm not sure why you think integrity constraints are purely logical. Primary keys are physical constraints. They enforce that the primary key remains unique. Here's an example of SQL that creates a physical foreign key constraint.

ALTER TABLE FactInventoryCollections
 ADD CONSTRAINT
  FK_FactInventoryCollections_ClientPK,
  FOREIGN KEY (ClientPK)
   REFERENCES ViewCubeDimClient(ClientPK);

Physical constraints allow the database engine to return an error if an operation attempts to insert a row that violates any defined constraints. --LinkedIn.com

2. To Laugh or Cry?

When One Data Model Just Won't Do: Polyglot Persistence

3. Online Debunkings

• Comments: Atomicity and its reinterpretation
• Comments: Corporate Data Model re-defined as Enterprise Data Model (EDM)

4. Interesting Elsewhere

David McGoveran has been working on a book tentatively titled LOGIC FOR SERIOUS DATABASE FOLKS intended to set some matters straight regarding the formal, set-theoretic and logic foundations of the RDM which have been misinterpreted. While he is not ready to publish yet, I asked and he agreed to post at his site a draft of a chapter on view updating which I consider a must read (together with the Introduction), particularly since it exposes the thinking behind the Principle of Orthogonal Design rejected by Date and Darwen.

• Introduction
• Can All Relations Be Updated?

David invites comments.


5. New Links

Added the following to the LINKS page:

• The database curmudgeon speaks again
• Synthesizing 3NF Relations from FD's
• KnowOS

6. And now for something completely different

Follow @DBDebunk Follow @ThePostWest

See  

The First Normal Form in Theory and Practice Part I