Database Design & Internals
Indexes, query planning, transactions and how databases are built.
Beginner
Start here. No background needed beyond school maths.
Document
Beginner
↗ External site
Database Normalization Description
A plain explanation of normalisation: why you split data into tables, the first three normal forms, and the trade-offs, with examples.
Sign up to see the source
Document
Beginner
↗ External site
DB-Engines Ranking
A monthly popularity ranking of database systems by type, handy for seeing which databases employers use and for comparing them.
Sign up to see the source