• FT Relation Interpretation
  
• L/C Tree Prediction in SQL 
  
• L/C "Purpose built systems"
• SMS Primary Key Immutability
• FT Kinds of Surrogate Key
• SMS Imaginary Keys 
• FT Uniqueness Is Relationship
• SMS SST/FOPL & Keys

Note: I am working on entirely new papers (not re-writes) in the PRACTICAL DATABASE FOUNDATIONS series. I have already published two:

THE FIRST NORMAL FORM - A DEFINITIVE GUIDE

PRIMARY KEYS - A NEW UNDERSTANDING

available for ordering from the PAPERS page, and two more:

RELATIONAL DATABASE DOMAINS: A DEFINITIVE GUIDE

DATABASE RELATIONS: A DEFINITIVE GUIDE

are in progress.

In the process I am coming across industry common and entrenched "pearls" that I am using for my "What's Right/Wrong with this Database Picture, or "Setting Matters Straight" (SMS), and "To Laugh or Cry" (TLC) posts on Linkedin. I do these posts to enable the few thinking database professionals left realize how scarce foundation knowledge is, and to illustrate fallacies that abound in the industry, of which they are unaware, and which the papers are intended to dispel.

Time permitting, I may specify those fallacies in brief posts that I set straight in the papers, such that those thinking professionals can test their knowledge and decide whether the papers are a worthy educational investment.

Here comes the first, a TLC I just posted on LinkedIn:

 “The company was using a [SQL] RDBMS . . . to handle data transactions for its trading applications. However, the applications required arbitrary data types, which is nearly impossible for relational systems, according to experts.”

which contains three fallacies--can you identify them before you proceed?