Data Modelling

Structure for correctness and speed. Keys and normalisation, dimensional modelling with star schemas, fact grain and slowly changing dimensions.

• Data Modelling: Normalisation, Star Schemas & SCDs — Designing data so it's correct and easy to use. Learn entities, keys (primary, foreign, natural, surrogate), normalisation (1NF, 2NF, 3NF) for OLTP, dimensional modelling for analytics (facts, dimensions, grain, star and snowflake schemas), conformed dimensions, fact types (transaction, snapshot, accumulating), slowly changing dimensions (types 1, 2, 3), Data Vault and One Big Table, and modelling in dbt — with runnable SQLite code implementing an SCD type-2 customer dimension and a point-in-time join.