Follow @DBDebunk Follow @ThePostWest

See

Weak Entities, Referential Constraints and the Conceptual-Logical Conflation

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

I use the word grain in the same sense as Kimball although I use it across Facts and Dimensions. I like the term over things like Uniqueness, Constraint, Key because it is a term that business readily understand, and can be used prior to the formal identification of a final key. In Dimensional Modelling it is a best practice for the Fact tables to have such a grain (a composite key across associated Dimensions) and is also necessary for many Dimensions (to assist with updates, type-2 logic etc.) - to the point where it is a best practice to identify the grain (Row Natural Key, Source Id, etc.) of the Dimension. The use of a surrogate key on either Dimensions or Facts must be backed by this level of rigor if data integrity is to be maintained. It also forces modeller consideration of source system issues such as multi-source key uniqueness, reuse of keys, deletions, etc. To clarify a little on Dimensions, the grain of an example type-1 customer dimension would be 'a customer id', the grain of an example type 2 customer dimension would be 'a customer id + as at time'. So 'grain' means the defined uniqueness for a row in the table. Generally, this also has the advantage of calling out poorly designed structures that have not established their relational uniqueness correctly - the cause of the irritating duplicate row issue in a Surrogate Key-oriented Fact table.--LinkedIn.com

Got that?

2. To Laugh or Cry?

• help me i was designing the database

3. Online Debunkings

• First normal form question
• The 'Real World' and Database Design
• Data Model: Neither Conceptual, Nor Logical, Nor Physical

4. And now for something completely different

Inside The Mind Of Leonardo

Fascinating.

Two books that every American should read (but won't).

• Matt Taibbi: DIVIDE - AMERICAN INJUSTICE IN THE AGE OF THE WEALTH GAP
• Michael Lewis: FLASH BOYS

@The PostWest

• Holocaust Inversion: “Gaza = Auschwitz”
• Obama’s Irrational Animus for Israel
• Allah_Islam: Say Goodbye to Europe and Civilization
• Israel and the PostWest: Denial, Illusion & Delusion
• It's The Jews, Stupid!

Follow @DBDebunk Follow @ThePostWest

My August Post @All Analytics

To ensure data operations make sense and results correspond to the real world and are interpreted correctly, analysts need to know the business rules on the basis of which a database was designed. Here are the types of rules for which they should be looking.

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

Follow @DBDebunk Follow @ThePostWest


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

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

Invoice number is the key (key is not unique in this table). Although structure or key constraints doesn't enforce uniqueness of rows, the assumption is there will not be duplicate rows. --LinkedIn.com

2. To Laugh or Cry?

Relational Queries by Reference

3. Online Debunkings

What is Weak Subtype

5. And now for something completely different

Tim's Vermeer

Fascinating

@The PostWest

• ISIS Bad, Hamas OK: Only One Difference
• Efraim Karsh: It's Anti-Semitism, Stupid
• Pinch Me
• The West Prefers to Deplore Dead Jews To Letting Them Defend Themselves
• Israel and the Arabs in War: Two observations
• Just Sayin'
• Obama to Israel: Do As I Say, Not As We Do
• Cairo talks: Deja Vu
• Reality Check
• Gaza Blame: Upside Down and Backwards

Follow @DBDebunk Follow @ThePostWest


Conveying data fundamentals to practitioners, losing neither rigor, nor the audience is a difficult task. There are many experienced professionals with tool expertise, but poor foundation knowledge for which there is little regard. Even in academia education has been substituted by training, which is not the same thing.

One dilemma faced by an educator is the tension between the simplicity of examples effective for conveying general concepts or principles and the complexity of the reality to be represented in databases. The latter requires integration of many concepts and principles, as well as thorough business knowledge. This is part of the reason why I normally refrain from specific online modeling/design advice and limit myself to the general principles that must be adhered to in the process.

Follow @DBDebunk Follow @ThePostWest

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)



 

Follow @DBDebunk Follow @ThePostWest


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.

Follow @DBDebunk Follow @ThePostWest


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.

Follow @DBDebunk Follow @ThePostWest

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.

Follow @DBDebunk Follow @ThePostWest


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.

Follow @DBDebunk Follow @ThePostWest


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.

Follow @DBDebunk Follow @ThePostWest


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

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

Logical design is where the Architect defines entities (which will become tables in a database), attributes (which will become columns in a database), etc. This is typically the level that SMEs are most comfortable. I think that a Logical design may deal with data types and keys, but it does not cater to any specific platform or engine.
Physical design is where the Architect translates the logical design into tables, columns, datatype specifics like INT versus NUMERIC, indexes, partitions, etc. This is where "the rubber meets the road" and the logical design gets mapped into a form that can exist and be tested on a database server.
While I'm sure that someone will object to this link on religious grounds, the discussion  does a pretty good job of making the distinctions that concern me. --LinkedIn.com

2. To Laugh or Cry?

MyBatis Schema Migration System

H/t Ben Samuel, who adds:

"From the department of "we haven't really thought this feature through" comes this gem, one of several schema migration systems that allow "reverse migrations" or "downward migrations". Whereas a forward migration creates tables, columns, etc., a reverse migration drops them. The video proudly shows them "reverse migrating" their database until all tables are dropped. Another vendor patiently explains why they don't offer this feature."

3. Online Debunkings

• Is the Relational Data Model Spent?
• 4 Table Types you Need to Scale a Relational Database
• A data model of the SAP Bill of Material Explosion tables
• What are people's opinions on nosql
• Is Data Science a combination of Data Architecture and System Engineering?

4. Interesting Elsewhere

The Death Of Expertise

5. And now for something completely different

The "productive" business and tech elite:

• Snapchat CEO Evan Spiegel 'mortified and embarrassed' over leaked emails
• Police-friendly tech CEO charged with hit-and-run
• Billionaire claims he owns the road, the beach and the tides
• Mystery millionaire hides $100 bills around US city ...
• Perkins On 'Nazi' Quote Inequality

God's given gift to humanity and pillars of society.

Follow @DBDebunk Follow @ThePostWest

May Post @All Analytics

What you need to know for the purposes of this discussion is that tables that bundle multiple entity classes have certain drawbacks. Normalization is a design repair procedure that unbundles the classes -- the columns representing attributes pertaining to each class -- each into its own table. This is possible if and only if there is no data lost or made spurious in the process -- that is, when a bundling of table A is mathematically equivalent to the joins of its unbundled projection tables B and C.

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



 

Follow @DBDebunk Follow @ThePostWest



1. Quote of the Week

Codd's relational model is based on set theory, and set theory simply doesn't work for database systems. It can't, for example, model a gum ball machine. Gum balls, you see, have only one attribute, which is color (gum balls don't have names, serial numbers, bar codes, or URLs). If you put 200 gum balls in a gum ball machine, the gum ball machines contains 200 gum balls. If you try to put 200 gum balls in a gum ball relation, you get a relation of 5 gum balls (the number of colors) and 195 duplicate errors. If you then take 5 gum balls out of the gum ball machine, it still contains 195 gum balls. If you take 5 gum balls out of the gum ball relation, it goes empty. --Jim Starkey, LinkedIn.com

2. To Laugh or Cry?

How to store and document large data models

3. Online

• How Many Data Model Layers Are Useful?
• Why Don't DBAs Join the NoSQL Revolution
• SQL NULL problems in analytics 

4. Interesting elsewhere

Software engineers think they're amazingly great 

5. And now for something completely different

• Pope John Paul II no saint, covered up sin
• Cardinal's vast luxury apartment in Vatican
• Man crushed to death by giant crucifix dedicated to Pope 

God keeps missing.

Follow @DBDebunk Follow @ThePostWest


UPDATE: Correction on 6/8/14


This is a response to comments by a reader on one of my posts.

L: I realize that you have taken much further what Codd wrote on the first page of his 1970 paper but it's still remarkable how many people in the data business are not able to refer to, let alone talk productively, about his "natural structure of data". And many treat RT as a fait accompli when it is still evolving, not to mention those who, as you've pointed out many times, treat SQL gizmos such as outer join as if they come from RT when they don't.

Follow @DBDebunk Follow @ThePostWest


1. I will give the following presentation

Big Data, Analytics and Normalization

"Big Data may offer analytical insights, but with almost certainty will produce really big lies from 100% correct data", particularly when data are from external sources. This presentation will demonstrate

• Why and how
• How to protect yourself

Wednesday, 5/14, 7:00pm
Microsoft San Francisco office
835 Market St.

For more information contact MGinnebaugh@designmind.com.


2. Quote of the Week

Q: How do we do data modeling in NoSQL DB and Big Data??? 
A: Define the schema hierarchically so that the tables in the schema including ER form a forest using a parent relationship i.e. each table has at most one parent key. Now the data retrieval and storage is done using these parent or ancestor keys. Look for google datastore documentation for more details. --LinkedIn.com

3. To Laugh or Cry? and Online

David McGoveran's comments posted last week are a response to the following LinkedIn exchange initiated by Jim Starkey of Rdb and Interbase fame:

Is the Relational Data Model Spent?

Given who Jim is, my instinct is to cry rather than laugh. This is also the Online item, as I participated in the exchange. Jim did not respond publicly to my challenges and claimed in private that I was trolling. You decide, but if I am a troll, so is David.


4. Interesting elsewhere

Do graph databases deprecate relational databases?

H/t Erwin Smout.


5. And Now for Something Completely Different

• One in four Americans 'do not know the Earth circles the Sun'
• Rich should get more votes, says billionaire Tom Perkins

No comment.

Follow @DBDebunk Follow @ThePostWest

UPDATE 1: I have added Jim Starkey's reply to David's initial response (with my brief comments) and David's reply to it below.

UPDATE 2: I have made a few minor corrections and fixed end-note formatting problems.

Follow @DBDebunk Follow @ThePostWest


1. I will give the following presentation

Big Data, Analytics and Normalization
"Big Data may offer analytical insights, but with almost certainty will produce really big lies from 100% correct data", particularly when data are from external sources. This presentation will demonstrate

• Why and how
• How to protect yourself

Wednesday, 5/14, 7:00pm
Microsoft San Francisco office
835 Market St., 7th Floor
San Francisco

For more information contact MGinnebaugh@designmind.com.


2. My April column @All Analytics:

Missing Data, Databases & Analytics

3. Quote of the Week

Q: Is it necessary to follow standards during SQL programming? 
 
A: Standards and Best Practices usually come from common sense. I want to point out that it is God given potential which one must realise and be conscious to utilize it for His glory. --LinkedIn.com

4. To Laugh or Cry?

A data model of the SAP Bill of Material Explosion tables

5. Online 

• Will Pattern Discovery Systems Trump Analyst's Rules-Based Models?
• Why don’t RDBMS products support sub-typing?
• Which of these two data model fragments is normalised and to what extent?

6. Interesting elsewhere

Big Data, Little Happiness

(requires free registration)


7. And now for something completely different

The Death Of Expertise

Today being the anniversary of the Holocaust, I decided to add the following:

Berlusconi's holocaust jibe provokes German outrage

The irony of Italians badmouthing the Germans about the extermination of Jews. But this time the former spoke the truth:the latter cannot have it both ways.

Follow @DBDebunk Follow @ThePostWest


As told by C. J. Date, sometime shortly after the introduction of SQL DBMS's in the industry, when non-relational products e.g. hierarchic and network reigned and the relational idea was a very hard sell, he and Michael Stonebraker (the author of Ingres and at the time a professor of Computer Science at University of California Berkeley) participated in a panel at a technical conference. The following is the (praphrased) exchange between them:

CJD: The reality is that most practitioners are too set in their non-relational ways and we cannot expect them to understand and appreciate the relational model. Rather, we must focus on the young generation of practitioners, who learn the relational model at university.

MS: Chris, you don't understand. I am teaching those youths: they were not around when we struggled with the huge problems of the pre-relational systems and they are reinventing all of them!

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

Now that we have seen a lot of information about NoSQL databases, it is interesting to drop back and look around at how much NoSQL stuff we already have in our organizations. I had never thought of a file system as a database, but it is. The comparison is fascinating. File systems don’t impose any structure on the data that is stored in any given file. There is a key value relationship to each file. There is little control over concurrency beyond file locking. This is very similar to NoSQL, with locking only at the aggregate level. File systems are cheap; everyone has one and they hold huge amounts of data on multiple nodes. --Book review, NoCOUG Journal

2. To Laugh or Cry?

Find GUID in Database

3. Online exchanges

• Consistency...when do you truly need it?
• Is there any difference between Fortress Model and Data Model?
• Which is better practice Composite Key vs Surrogate Key?
• Big data 5nf-fifth normal form
• How to model ternary associative entity with a binary constraint?

4. Interesting elsewhere (corrected first link and added a second):

• CREATE ASSERTION Impossible Dream (by Erwin Smout)
• Why ASSERTIONs Are Important (by Toon Koppelaars)

5. And now for something completely different

Joe Biden wants to nominate Obama for sainthood

The VP of the world's "superpower".

Stanford opening new lab to study bad science

And tomorrow we'll need a lab to study bad science in the study of bad science.

Follow @DBDebunk Follow @ThePostWest

In What the $&@#^ is Applied Big Data, venture capitalist Greg Sands raises an issue about which I as a scientist (and not just a "data scientist") have often expressed concern. 

"The world is awash in data. Figuring out what to do with it is the problem. The press is littered with reports about Big Data. Many CIOs report that their CEOs have come to them and said, “We need some of that Big Data.” That often means make sure we’re collecting all the available data, often deploying a new Hadoop-based infrastructure to store and analyze it. After this elaborate process and extensive investment, they’ll start mining to figure out if there are critical insights that come out of the data. We see many entrepreneurs that start the same way. Aggregate data and look for a problem."

Follow @DBDebunk Follow @ThePostWest

In a LinkedIn exchange I argued that an optimal generality-to-simplicity ratio (ability to represent a maximal range of reality with minimal complexity) and a 1:1 correspondence between informal business modeling constructs and formal logical database constructs are beneficial. And I claimed that insofar as data models that are formally defined are concerned, the relational model scores best on both.

One of the responses I got was

GE: Though I might come up with slightly different lists, in general, I agree with your expression of criteria for selecting a primary key and of generality and simplicity, but disagree with your conclusion that "RM scores better than any other modeling scheme."

Let me take his points one by one.

Follow @DBDebunk Follow @ThePostWest


Note: I usually receive notifications of comments to my posts, which I then publish if they are not spam. Today, however, I noticed a whole bunch of old comments that were waiting for moderation, some of 2013, of which I was not notified. I have just published them and replied. Apologies to the commenters.

1. Quote of the Week

Schemaless describes the storage engine, not the data. Data has schema. No Data is ever Schemaless. Schemaless DBs merely describe a feature of themselves, not the data they store. Namely that they don't store and enforce this schema in addition to the data.
One advantage of this Is that you can change the schema "easily" - helps with up time. Now if you don't evolve the old data with each schema change you can end up with multiple schemas stored in your backend and no way of knowing which data is of which schema without some form of analysis of the data. Show me the Front end that can deal with evolving schemas without knowing about them ;) Point being Schema's always there wether any tier deals with it explicitly or not. Something has to manage it. --LinkedIn.com

2. To Laugh or Cry?

Big data means the reign of the relational database is over

3. Online

What is the best way to explain Normalization 1NF,2NF and 3NF

4. And now for something completely different

Samsung’s entire leadership team is paid less than individual executives at Google, Apple

Follow @DBDebunk Follow @ThePostWest


Note: This is a 11/06/17 revision. Thanks to Erwin Smout for his review of a draft and suggesting improvements.

The claims that (1) the relational data model (RDM) is old and, by implication, obsolete -- the industry has purportedly "progressed" -- and (2) promoting it as a superior alternative to NoSQL, Hadoop and other "modern" data management technologies is "religious" in character are routine. They have popped again in a LinkedIn exchange and I responded as I usually do, by asking why is the promotion of a scientific approach deemed religious, while pushing ad-hoc alternatives is not?

Follow @DBDebunk Follow @ThePostWest


1. My presentation at SQLSaturday:

The Last NULL in the Coffin: A Relational 2VL Solution to Missing Data
March 15, 2014 11:15am
Microsoft Technology Center, 1065 La Avenida, Building One, Mountain View, CA, 94043

2. Descriptions of all available courses are now posted on the SEMINARS page. Contact me if you are interested in public or private sessions, with possible customization for particular needs.

3. Quote of the Week

1: - a picture is only one representation of a data model: What is the adequate data structure to store a data model: Picture, Text (UML), formal (Gellish), Database) - is there an API to access, create and manipulate data models - do you handle hundreds of types (Entity, Relationship, Attribute): - do you handle one conceptual data model and derived consistent (external) submodels - document : which meta-attributes must be maintained to describe the elements of the data model. How to create different views of the data model (Pictures with different views, detailed printed documents)
2: - How to check the data model with instance data and queries based on the requirements.
3. - Use the ER-Model for Instance data (instead of the relational model) and thereby avoid the impedance mismatch:
4: A query language to access instance data which is based on the Entity-Relationship-Model and NOT on the relational model" --LinkedIn.com

Ugh!

4. To Laugh or Cry?

mysql - additional information on normalization 

5. Online

Do you use Composite Primary Keys to design a good, solid data model?

6. Elsewhere

http://image-store.slidesharecdn.com/a606a81e-9bd4-11e3-8016-22000a9aa8cc-large.png

The database field.

7. And now for something completely different

Zombie Studies Gain Ground on College Campuses

Follow @DBDebunk Follow @ThePostWest

The term "distributed" is thrown around a lot these days. Hype notwithstanding, just as with analytics and data science, distribution in data management is nothing new.In fact, SQL vendors (IBM, Sybase, Ingres, Oracle) -- frequently criticized today for non-scalability -- tackled distribution decades ago. The non-relational systems preceding SQL were not amenable to it, and SQL is the closest to the relational model the industry allows you to get. 

Follow @DBDebunk Follow @ThePostWest


I very much doubt that somebody who does not think logically can be a fully competent database professional. From a LinkedIn exchange, an attempt to "address some of my points by calling them out":

JL: You said: "... much of the underlying motivation of NoSQL stuff is anti-relational ..." Okay, so? Data management in graph/document/columnar dbs is not possible because they are "anti-relational"?

The point I made was that, name notwithstanding, NoSQL vendors/proponents are not just anti-SQL, they are actually anti-relational, an important difference.

• What exactly does this have to do with whether graph/documents/columnar database systems "are possible or not"?
• Columnar DBMS's can be relational and are not considered NoSQL products.
• At issue is not the possibility of graph/document systems, but what they are appropriate for.

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

A view is a logical table based on one or more tables or another view.View can be thought as a virtual table which takes the output of a query and stores it ... A View can be based on a table or another view.--dwhlaureate.blogspot.in

2. To Laugh or Cry?

Will physical modelling and normalization make sense in next decade?

3. Online

Database design patterns

4. Elsewhere

I was reading the following

How Edward Snowden went from loyal NSA contractor to whistleblower

which is interesting in itself, when I came across this:

In mid-2006, Snowden landed a job in IT at the CIA. He was rapidly learning that his exceptional IT skills opened all kinds of interesting government doors. "First off, the degree thing is crap, at least domestically. If you 'really' have 10 years of solid, provable IT experience… you CAN get a very well-paying IT job," he wrote online in July 2006.

Should be familiar to my readers.


5. And now for something completely different  

• Less than half of US Republicans now believe in evolution 
• One-third of Americans reject evolution

Who says Congress is not representative?

Martin Kramer is, IMO, possibly, the most astute analyst of the Middle-East: 

• Beware an Alliance of the Weak

Follow @DBDebunk Follow @ThePostWest

 REVISED: 10/18/16

Many common misconceptions are excellent indicators of poor grasp, if any, of  the relational data model (RDM). One of the most entrenched is the notion of "denormalization for performance".

I will not get into the first four of the 5 Claims About SQL, Explained. I do not disagree with the facts, except to point out that the problems are not due the relational nature of SQL and its implementations, quite the opposite: it is due to their poor relational fidelity. I will focus on the fifth, "Should everything be normalized?"

Follow @DBDebunk Follow @ThePostWest


1. Quote of the Week

Observe the trend of NoSQL growth, revenue will trail along irrespective. In the industry, only with respect to non-OLTP applications, RDBMS is in "keep the lights on" state by necessity, it is either awaiting obsolescence/end of life, or replacement with NoSQL solution; no longer a "workhorse" - this was the discussion point. --LnkedIn.com

2. To Laugh or Cry?

Why semantic models like RDFOWL, TMDM, are not sufficient for the web of linked data

3. Online

Why don’t RDBMS products support sub-typing?

4. Elsewhere

Cisco unveils 'fog computing' to bridge clouds and the Internet of Thing

Could not have thought of a better name!


5. And now for something completely different 

Follow @DBDebunk Follow @ThePostWest

In analytics, it's much easier to "fish" for correlations and try to explain them post-hoc than to develop mutually exclusive hypotheses up-front and test empirically which one holds.Only the second approach is scientific, though, hence my skepticism about the hype of business analytics as "data science." 

Follow @DBDebunk Follow @ThePostWest


1.  Quote of the Week

I do not understand your first point. Even a database designed with only 1NF can have integrity if other methods are used to ensure that integrity. [Higher n]ormal forms can guarantee the absence of various integrity issues, but the lack of a normal form does not guarantee the presence of the integrity issue. I remember writing pages of code to do just that in the early days of RDBMS products before normal forms (i.e., referential integrity) was strictly enforced by the DBMS. --LinkedIn.com

Note: My (first) point was that the minimal relational mandate is 1NF, but that full normalization (5NF) is desirable for practical reasons.


2. To Laugh or Cry?

What is difference between storing data in traditional and modern way in database?

3. Online

What is Surrogate Key, why it is used, is it Primary Key?

Apropos my just published paper on keys.


4. Data management is important, after all.

Point-of-sale malware infecting Target found hiding in plain sight

(Note the last sentence in the article).

So is database design

Poor Data Management Blinded Chase to Madoff Fraud

5. And now for something completely different

• Why It Makes Sense to Pay Beautiful CEOs More 
• What are the Best Looking Data Models 
• THE VISUAL ORGANIZATION

Looks like a pattern.

Follow @DBDebunk Follow @ThePostWest

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

Follow @DBDebunk Follow @ThePostWest


Conveying the theoretical foundation of database management to practitioners without losing either precision/rigor, or the audience is a non-trivial endeavor, the skill for, or interest in which very few possess. More often than not one or the other are lost.

In Relations and Relationships I referred to the following LinkedIn exchange:

AT: ... William Kent and his book "Data and Reality" [1978] ... is devoted to "attributes", and (in my words) William confesses that he can not distinct [sic] between "relationships" and "attributes". Thus, the later might be completely redundant. 

GE: This confusion of entities vs. attributes has been with us a long time. Several years ago [a student] ... discovered a paper ... that discussed this dilemma. He proposed calling the thing, which we could not determine whether it was an entity or an attribute, an "entribute." Beautiful, eh? That was in 1939.

Follow @DBDebunk Follow @ThePostWest


1.  Quote of the Week

As you might have gathered, I think NoSQL is technology to be taken very seriously. If you have an application problem that maps well to a NoSQL data model - such as aggregates or graphs - then you can avoid the nastiness of mapping completely. Indeed this is often a reason I've heard teams go with a NoSQL solution. This is, I think, a viable route to go - hence my interest in increasing our understanding of NoSQL systems. But even so it only works when the fit between the application model and the NoSQL data model is good ... And of course there are many situations where you're stuck with a relational model anyway. Maybe it's a corporate standard that you can't jump over, maybe you can't persuade your colleagues to accept the risks of an immature technology. In this case you can't avoid the mapping problem.
--martinfowler.com

2. To Laugh or Cry?

Which database type to use (one big database or many smaller)?

3. Online

Check out the last update's exchange--more comments have been posted since:

RELATIONAL DATABASE

4. Elsewhere

Set In Stone

5. And now for something completely different

Multivitamins Doctors Say Stop Taking Them

Half of U.S. adults take vitamins, supplements routinely

Draw your own conclusion.