When you work with a database, the way you structure and access the data affects almost everything built on top of it. A poorly chosen schema can make common operations difficult, an unnecessary join can slow down a query, and a missing index can turn a simple lookup into an expensive operation as the data grows.<\/p>\n\n\n\n
That means you\u2019ll work with several connected areas when building your database skills: relational models, SQL, schema design, keys and constraints, normalisation, indexing, transactions, query optimisation, and different types of data stores. The depth you need in each area depends on the role, so the database skills expected from a backend engineer can differ from those needed for a data engineer or database administrator.<\/p>\n\n\n\n
This guide takes you through these areas in the order you\u2019re likely to encounter them, from relational and SQL fundamentals to schema design, indexing, query performance, transactions, and modern data stores. Along the way, the focus is on applying each concept to real development problems and understanding the decisions behind how a database is designed and used.<\/p>\n\n\n\n\n