Monday, March 23, 2020

TYFK: How (Not) to Compare NoSQL Systems and RDBMSs?

Note: About TYFK posts (Test Your Foundation Knowledge) see the post insert below.
“But if you still want to compare NOSQL databases with RDBMS, they primarily vary in
1. "normalization" where RDBMS contains normalized (upto certain degree) data and NOSQL based database contains non-normalized data;
2. RDBMS based databases are (I MUST say, generally and it isn't a criteria) fully ACID compliant while NOSQL databases are partially ACID compliant.
3. RDBMS are much slower and difficult to scale while NOSQL databases are much faster and easily scalable.
4. RDBMS normalization was very useful 50 years ago when cost of disk and memory was high, and computation power was limited. With the revolution in computing power, cheapest disk and memory availability has made RDBMS normalization a matter of joke - many people do not really understand why they need to normalize data in today's time.”
First try to detect the misconceptions, then check against our debunking. If there isn't a match, you can acquire the necessary foundation knowledge in our POSTS, BOOKS, PAPERS, LINKS or, better, organize one of our on-site SEMINARS, which can be customized to specific needs.

Note: In what follows RDBMS refers to a truly relational DBMS (of which currently aren't any), not to be confused with a SQL DBMS.

Thursday, March 12, 2020

Muddling Modeling Part 2: An Example

In an old article I used a Hay-Ross exchange to illustrate how disregard for fundamentals and the associated name proliferation -- which underlies the industry's fad-to-fad tradition -- cause confusion that inhibits understanding of conceptual modeling for database design. A recent LinkedIn exchange -- hardly unique -- showed the article to be as relevant today as it was two decades ago, prompting me to bring it up to date.

In Part 1 we reiterated pertinent fundamentals. Here is the re-written article
-- try to apply the fundamentals from Part 1 before you proceed with our debunking.

Sunday, March 1, 2020

Muddling Modeling Part 1: Fundamentals

“Data modelling, star schema, snow flakes, data vault. Implementing virtual data warehouses (many stage to modify relationships). Normalisation (using a lot of surrogate keys) all for the sake of business reporting analytics. Reason a SQL DBMS approach columns rows is mandatory.”

This recent "comment" reminded me of a decades-old article I published in response to a critique by David Hay of the "fact model" then newly proposed by Ron Ross as an "alternative to the data model". In a Letter to the Editor, Hay correctly observed:
“In our industry, there is a strong desire to put names on things. This is natural enough, given the amount of information that we have to classify and deal with in our work. To give something a name is to gain control over it, and this is not necessarily a bad thing. The problem is when the name takes the place of true understanding of the thing named. Discourse tends to be the bantering of names, without true understanding of the concepts involved.”
of which the above comment is an exquisite example.
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