Rules for Data Modeling with DynamoDB

Re:Rules for Data Modeling with DynamoDB by mabbo on Wednesday April 08, 2020 @04:00PM (#22816460)

I'm reminded of being 18, my first year of college, and I had this lovely database professor who was good with crowds. He'd get us all to memorize and repeat, as a group certain phrases.

"Why do we normalize?"

150 students, in unison: "To make better relations"

"And why do we DE-normalize?"

150 students, in unison: "Performance"

"And what is a database?"

150 students, in unison: "A self-describing set of integrated records"

That was 16 years ago, and I'm still able to say those answers verbatim.

[ Parent | on HN ]

Re:Rules for Data Modeling with DynamoDB by __afk__ on Wednesday April 08, 2020 @06:43PM (#22818009)

Self-describing?

Maybe to someone who could make sense of the DDL and read the language the label col names are written in. And understand all the implicit units, rules around nulls/empties, and presence of magic strings (SSN, SKU) and special numbers (-1) and on and on. For that you need something like RDF and a proper data model.

[ Parent | on HN ]

Re:Rules for Data Modeling with DynamoDB by Ari_Ugwu on Thursday April 09, 2020 @08:46AM (#22821982)

Aren't you conflating the lexicon of data management with specific implementations of a relational database management system (RDBMS)?

Sorry, but your response sounds snarky and reminds me of all the ego hurdles I had to overcome when leaving/loving databases and set theory. Please remember that your comment could be someone's first introduction or step early step in learning.

[ Parent | on HN ]

Re:Rules for Data Modeling with DynamoDB by bambambazooka on Thursday April 09, 2020 @02:40AM (#22820348)

If you use Oracle, PostgreSQL or MySQL (those are the ones I'm familliar) you can always query the data dictionary and see how your tables relate. For me that is self-describing.

[ Parent | on HN ]