4.3. Structure of Relational Database
Relational database system has a simple logical structure with sound theoretical foundation. The relational model is based on the core concept of relation. In the relational model, all data is logically structured within relations (also called table). Informally a relation may be viewed as a named two-dimensional table representing an entity set. A relation has a fixed number of named columns (or attributes) and a variable number of rows (or tuples). Each tuple represents an instance of the entity set and each attribute contains a single value of some recorded property for the particular instance. All members of the entity set have the same attributes. The number of tuples is called cardinality, and the ...
Get Database Systems: Concepts, Design and Applications now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
