Sunday, November 19, 2017

This Week

1. Database Truth of the Week

"Codd's original 'normal form' in 1969-70 is not equivalent to the current 1NF. The former and 'normalization' were tied to Codd's first definition of join in 1969. Multiple normal forms (1NF-5NF) and 'further normalization' are a consequence of Codd's re-definition of join in 1970 as the one of today. Once 1NF and further normalization to at least 2NF have been introduced, 'the one normal form' makes no longer sense. Thus, there is no way to answer "what is the difference between the normal form and 1NF" without taking into account the definition of join, and -- if defined as we now do -- no way to understand the former, except to say that it was to the 1969-70 join what the 5NF is to the current join.That is one reason I personally strongly believe that while relations are at least in 1NF -- a relation that is not, cannot be represented formally as a relation, nor do the formal operators of the relational algebra work correctly otherwise -- even this is insufficient and formal relations must be in 5NF. Otherwise put, there is no such thing as a non-5NF database relation." --David McGoveran

2. What's Wrong With This Database Picture?

"A relation is a data structure which consists of a heading and an unordered set of tuples which share the same type", according to Wikipedia on 'Relation (database)'."
"In SQL RDBMSes (such as MS SQL Server and Oracle] tables are permanently stored relations, where the column names defined in the data dictionary form the "heading" and the rows are the "tuples" of the relation."
"A relation can be represented by a table in database. A relation in the context of modeling a problem will include the fields and possibly the identification of fields which have relationships with other relations..."
"Put simply, a "relation" is a table, the heading being the definition of the structure and the rows being the data."
"In simple English: relation is data in tabular format with fixed number of columns and data type of each column. This can be a table, a view, a result of a subquery or a function etc."
"A relation is a table, which is a set of data. A table is the result of a query." --What is a relation in database terminology?,

3. To Laugh or Cry?

"If I have an address '1353 Main St, Anytown, CO, 80111' [t]hat address can be kept together, or it could be broken down like this:
(some key) |1353 Main St| Anytown| CO| 80111
Which together makes a relation." --What is a Relational Database?,

4. Housekeeping

A new set of labels is up. In order to work around Blogger limitations, they are mostly abbreviations or acronyms of the terms listed on the FUNDAMENTALS
page, which was updated to what is hopefully the final draft -- the terms, abbreviations and acronyms that are used as the new set of site labels are marked in red. 

The 2017 posts, including the earlier posts that were rewritten in 2017 are being re-labeled. As other old posts are rewritten, they will also be relabeled. In the meantime, only the few old labels that remain in the new list will work with not yet rewritten older posts -- use Blogger search instead

For detailed instructions on how to understand and use the page and the new labels, see the ABOUT page, that was also updated.

5. Publications 

6. Oldie but Goodie

Fabian Pascal and RDBMS deficiencies in fully implementing the relational model

7. Elsewhere

Business Rules! Belong to Data Models or Applications? (see my comments in the exchange).

8. Of General Interest

And Now for Something Completely Different: The PostWest

Article of the Week

America's  Myth of Free and Efficient Markets: Myths of the 1 Percent - What Puts People at the Top

Video of the Week

The Trump Presidency (video) is quite representative.

Book of the Week


Decline, demise and moral turpitude

The Sillicon Valley State: Mechanism of Tyranny and Destruction of Free Civilized Society

Anti-Semitic Hypocrisy, the Myth of a "Palestinian nation" and the Illusion of a "Peace Process"

I will not publish or respond to anonymous comments. If you want to say something, stand behind it. Otherwise don't bother, it'll be ignored.

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