4.4. Synthesising a Database Schema by Composition
Given a set of FDs, we may synthesise the schema of a relational database algorithmically. We can do this in either of two ways: by composition or by decomposition . We first discuss two compositional methods: a graphical method and an algebraic method.
4.4.1. Functional Dependency Graphs
A functional dependency graph (FD graph) is a special kind of abstract schema . The vertices of an FD graph are domains, either simple or composite, and its edges are always functions between domains, rather than more general relations. The FD graph is closer to a database schema than an E-R diagram, because a relational database can only model functional dependencies.
Because a relational database instance excludes ...
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