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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

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See  

The First Normal Form in Theory and Practice Part I

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1. Quote of the Week

I have been in the data side of IT for quite some time now and have seen the evolution of how data is ingested, manipulated and regurgitated to the end users in hope of telling our consumers "how much of something did something". The main issue seems to be complexity of the data models and the fact we don't have a model that can expand with the data without adding tons of new schema. The solution.  --LinkedIn.com

2. To Laugh or Cry?

• i have a table with 4 FK's, help me with query to find the tables

3. Online Debunkings

• Comments on The Conceptual-Logical Conflation and the Logical-Physical Confusion
• Comments on 1NF Is Not Structural Regression

4. Interesting Elsewhere

• Knowledge-Based Trust Estimating the Trustworthiness of Web Sources
• Google wants to rank websites based on facts not links

5. And now for something completely different

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March blog post @All Analytics:

They should be represented in the database by integrity constraints -- not perfect substitutes, because they are very loose approximations to the rules -- but if they are enforced in the database by the DBMS they are usually recorded either in the definition statements that created the tables and constraints, or the database catalog.

Read it all

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See the series starting at

The First Normal Form in Theory and Practice Part I

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March 28, 11:15,  Mountain View

MEANINGLESS, BUT CONSISTENT: DATABASE TRUTH VS. CORRECTNESS

You're a SQL Server ace: your ability to squeeze everything from SQL and your performance tuning skills are unparalleled, but do you know what your tables really mean and, therefore, what queries make sense and whether results are correct and their interpretations sensible? This is a critical part of data fundamentals, the grasp of which is poor. It is a subject usually neither much covered in education, nor part of job requirements and industry dialogue, yet can defeat the entire purpose of your DBMS expertise. This presentation covers

• Meaning, business rules and table interpretations;
• Types of business rule; 
• Meaning and database truth; 
• Business rules, integrity constraints and database consistency; 
• DBMS and user reponsibilities.

Session Level: Intermediate

Event full details

Contact: Mark Ginnebaugh  mark@designmind.com

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1. Quote of the Week

what is an index in database? how can it make the search faster? please help me understanding this. Project Manager Technical
--LinkedIn.com

Note the job title.


2. To Laugh or Cry?

Tableau Data Modeling Resolving Many to Many Relationship

3. Online debunkings

Comments on Codd's Marks are not SQL's NULLs

4. Interesting elsewhere

• Lies, Damn Lies And The Myth Of Following The Data
• Surviving Data Science at the Speed of Hype

5. And now for something completely different