Computing · 1970

Relational model

Data as tables, queried by what you want, not how to find it.

Edgar F. Codd at IBM proposed storing data in relations with a mathematical query algebra. It separated logical data from physical storage and underpins nearly all business databases.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 2

Hard disk drive 1956
Set theory 1874

What it led to 1

SQL 1974

Related measurements

The dashed line marks when it first worked.

Cost of memory and storage Latest: Memory: 1.09k $/TB (2023) Source: Our World in Data