Seven Databases in Seven Weeks, 2nd Edition

Genres Redux

You’ve seen that how databases store their data can be largely divided into five genres: relational, key-value, columnar, document, and graph. Let’s take a moment and recap their differences and see what each style is good for and not so good for—when you’d want to use them and when to avoid them.

Relational

This is the most common classic database pattern. Relational database management systems (RDBMSs) are set-theory-based systems implemented as two-dimensional tables with rows and columns. Relational databases strictly enforce type and are generally numeric, strings, dates, and uninterpreted blobs, but as you saw, PostgreSQL provides extensions such as array or cube.

Good For:

Because of the structured nature of relational ...