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My July Post @All Analytics

When, for analytical purposes, you combine data extracted from database tables whose real-world meaning you don't know, you're asking for trouble. The meaning, after all, isn't in the tables. Rather, the meaning is contained in the business rules on the basis of which the tables were designed and which are approximated in the database with integrity constraints. Interpreting results on the basis of just visual inspection of the tables therefore involves guesswork and is almost certain to be wrong.

Read it all. (And please comment there, not here)



 

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1. Quote of the Week

Q: In a nutshell, what does RDF based Linked Data facilitate?
A: The ability to find and describe stuff using attributes (relations, properties, features, fields, characteristics). --LinkedIn.com

2. To Laugh or Cry?

Data Model now offers Relationship Modeling

3. Online Debunking

Data Vaults - Why Or Why Not

4. Elsewhere

• Conceptual vs. logical modeling, part III
• Conceptual vs. Logical modeling, part IV   

 
5. And now for something completely different

In its decline, theWest is becoming impotent and increasingly irrelevant in world affairs e.g. Russia, Syria, Iraq, Afghanistan, China, Libya, you name it. It is taking hypocritically its frustration on Israel and the Jews--its classic scapegoating during crises--reinforced by fear from internal Islam.

I am restarting my PostWest blog and will link regularly to posts in this section.


Critical comments that

• fail to show my facts to be false; or, if they are true, that my conclusions do not follow;
• are posted anonymously

will not be published and addressed.

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1. Quote of the Week

Don't confuse Data(base) Modeling with Business Modeling. All DBA are correct when they are talking about Database Modeling. If you want to ensure unique record on Business level, just add a unique composite index. (not as Key). But far to often, a unique record on business level is not ALWAYS unique (only most of the time) --LinkedIn.com

2. To Laugh or Cry?

Create database vs schema

3. Online Debunkings

• Big data means the reign of the relational database is over
• Conceptual Muddling and Database Kludges
• What do Data Scientists and Unicorns have in Common

4. Interesting Elsewhere

• Conceptual vs. logical modeling, part II
• Conceptual vs. Logical modeling (once again)

5. And now for something completely different

• S.F. housing prices bidding wars fiercer than ever
• Pinterest Threatens Long-Time San Francisco Tenants With Eviction
• San Francisco Protests at the Home & Office of David McCloskey
• San Francisco's guerrilla protest at Google buses swells
• Few applicants for blue-collar jobs in S.F.
• Shame of the City-Homeless in San Francisco
• A decade of homelessness - Thousands in S.F. remain in crisis
• AngelHack CEO's Attack On Homeless
• S.F. to offer George Lucas prime lot for his museum

 And if you like what they're doing to San Francisco, you'll love what they'll do to other cities:

Google Exec Rises Ire in Portland

 Symptoms of societal malaise.

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My June post @All Analytics

Combining data extracts from databases for analytical purposes without knowing what the source database tables mean -- what exactly in the real world they represent -- can produce wrong results.

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The common and entrenched misconception about normalization was recently visible yet again in a LinkedIn exchange.

R: Unless the need is for ACID compliant transactions, denormalization is generally not considered logically, physically or whatever-ally-–so essentially a thoroughly normalized mode is relevant for a write-infrequently consumption of data and data integrity can be guaranteed by design.

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I have corrected a mistake in For Codd's Sake: a mathematical relation is not the Cartesian product (CP) of the domains over which it is defined. Two readers correctly pointed out what I actually wrote myself in my business modeling paper:

Mathematically, a relation on domains—which are sets of values of a type—is a subset of the Cartesian product of the domains.

Note that the whole CP is also a subset, so it is also a relation, which happens to have useful applicability to business modeling and database design. In the database context, it can be pictured as the pool of all possible rows--past, present and future--for a R-tablevar defined by the domains' types. A database R-table is the set of actual rows at any point in time that is consistent with the set of all integrity constraints to which the R-table is subject (see Business Modeling for Database Design).


1. Quote of the Week

NoSQL usant correct m'y indeed totof n'y most of the dev ans devops who clearly thing nosql Means they will ne a le to do whatever they wants ans still have answers to their twisted query in a correct time. Those people see nosql as the mean to get ris of DBAs. And il not kiddin since it's happening right now un many companies i know of. --LinkedIn.com

2. To Laugh or Cry?

Architecting IMS for Big Data - a symbiotic relationship.

3. Online 

• Database Design Patterns
• Will Pattern Discovery Systems Trump Analyst's Rules-Based Models
• How do we do data modeling in NoSQL DB and Big Data

4. Interesting Elsewhere

IEEE Computer Issue on CAP Theorem

H/t Erwin Smout.


5. And now for something completely different

• Beyonce and Miley Cyrus studies offered at US colleges
• Better than Scientology: The new Zuckerberg-based religion

The PostWest.

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See: Name the Relational Violation Part 1: Conditional Uniqueness Constraint