Chapter 5. Relational Algebra
In the previous chapters, we have looked at defining a particular kind of relation, called a base relation, which will be given a physical representation in the database. The relational model also supports the creation of several kinds of derived relations. A derived relation is a relation that is defined in terms of other relations rather than in terms of attributes. These named relations can be base relations or other derived relations, in any combination.
In the database schema, a base relation is represented by a table. Derived relations are represented by views in Microsoft SQL Server and queries in the Microsoft Jet database engine. For the sake of linguistic simplicity, I’ll use the term “view,” since it’s the ...
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