Mapping between layers 2
- Regardless
of what approach we take, we need
- A vocabulary of data model
components
- An attachment of that vocabulary to
types
- Sample
vocabularies
- entity, relationship, collection
- table, row, column
- instance, variable, list, dictionary
- Specifying the mapping first at the abstract level, and then specialising
to a particular implementation, seems a good compromise
- The first mapping can be specified in the schema for locality and interoperability
- The second outside it for modularity and utility
