www.entitymodelling.org - entity modelling introduced from first principles - relational database design theory and practice - dependent type theory
The existence and ownership of particular phone numbers may be communicated or stored independently in which case they have the message structure:
The world as a whole now is communicated as :(11) |
This world view given by the message scheme (11) is an example of a relational schema. In summary, we have two possible ways of describing the world view in messages, the relational one (11) and the hierarchic1 one shown in full in (12).
(12) |