Saturday, March 21, 2015

Weekly Update



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

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.
David invites comments.


5. New Links

Added the following to the LINKS page:

6. And now for something completely different

Saturday, March 7, 2015

Weekly Update (UPDATED)




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?

3. Online Debunkings

4. Interesting Elsewhere

5. And now for something completely different

Thursday, March 5, 2015

Domains, R-tables, and SQL



March blog post @All Analytics:

To ensure sensible results from and correct interpretations of analysis of data from SQL tables or extracts thereof, analysts must know the tables’ interpretation -- the business rules underlying them -- which is rarely documented.

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




Wednesday, February 25, 2015

SQLSaturday Presentation




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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