Data Abstraction

Since many database-system users are not handy with computers, developers hide certain complexity details through several levels of abstraction in order to make it easier for users’ interaction with the system.

·     Physical level: The lowest level of abstraction describes how data are actually stored. It describes complex low-level data structures in detail.

·        Logical level: The next-higher level of abstraction describes what data are stored in the database, and what relationships exist among those data. It describes the entire database in terms of a small number of relatively simple structures. Database administrators use the logical level of abstraction who must decide what information to store in the database.

·     View Level: The highest level of abstraction describes only part of the entire database. In this level users need to access only part of the entire database. The level simplifies the interaction of users with the system. The system  may provide many views for the entire database.

I am writing a book on Databases. In the current blog, I will give you every Friday morning BDT time, small excerpts on Databases from my book in order to brush up on the subject. My eBook on Databases is a copyright in 2015 by me, Rosina S Khan. No part(s) or whole of these excerpts may be used or reproduced in any form whatsoever, without written permission by the author.