August 2009
Intermediate to advanced
893 pages
26h 48m
English
Content preview from Database Systems: Concepts, Design and Applications
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
6.2. Basic E-R Concepts
E-R modelling is a high-level conceptual data model developed to facilitate database design. A conceptual data model is a set of concepts that describe the structure of a database and the associated retrieval and update transactions on the database. It is independent of any particular database management system (DBMS) and hardware platform. E-R model is also defined as a logical representation of data for an enterprise. It was developed to facilitate database design by allowing specification of an enterprise schema, which represents the overall logical structure of a database. It is a top-down approach to database design. It is an approximate description of the data, constructed through a very subjective evaluation of ...