Relational database management systems

SQL or RDBMS databases have two main types, which describe the way data is stored on disk:

• Row-orientated
• Column-orientated

The different methods of storing the data and how it is arranged will offer very different performance patterns (that is, fast at some things but slow at others), and knowing about the right type to use can greatly improve the performance of your application. While both database types may appear very similar on the surface, they are quite different under the hood.

In the exam, there may be a question around a customer use case and asking which database would be the best fit.

First, let's look at row-orientated, which is the more common database system.

Row-orientated databases

In a row-orientated database, the data is stored in tables in normalized form (we discussed this in the SQL databases section) with links or keys between them.

Row-orientated databases store the data in continuous...