Relational modelling, normalization, and query design — from entity-relationship diagrams through to a working schema.
Before 1970, a database's internal storage layout and the way applications queried it were tightly coupled — change one and the other broke. Edgar Codd's proposal was to describe data purely as relations…
Relational modelling answers a specific question well: given a domain with unpredictable, ad-hoc queries and a need to keep facts consistent as they're updated, how should data be organised? Normalization's answer —…