DBMS Basics - Technical Questions and Answers

DBMS - Database Management System
DBMS - Basics

11.

What is Data Independence?

12.

What is a view? How it is related to data independence?

13.	What is Data Model?
	Answer: A collection of conceptual tools for describing data, data relationships data semantics and constraints. Workspace Report errors ... Name : Email: View Answer

14.	What is E-R model?
	Answer: This data model is based on real world that consists of basic objects called entities and of relationship among these objects. Entities are described in a database by a set of attributes. Workspace Report errors ... Name : Email: View Answer

15.	What is Object Oriented model?
	Answer: This model is based on collection of objects. An object contains values stored in instance variables with in the object. An object also contains bodies of code that operate on the object. These bodies of code are called methods. Objects that contain same types of values and the same methods are grouped together into classes. Workspace Report errors ... Name : Email: View Answer

16.	What is an Entity?
	Answer: It is a 'thing' in the real world with an independent existence. Workspace Report errors ... Name : Email: View Answer

17.	What is an Entity type?
	Answer: It is a collection (set) of entities that have same attributes. Workspace Report errors ... Name : Email: View Answer

18.	What is an Entity set?
	Answer: It is a collection of all entities of particular entity type in the database. Workspace Report errors ... Name : Email: View Answer

19.	What is an Extension of entity type?
	Answer: The collections of entities of a particular entity type are grouped together into an entity set. Workspace Report errors ... Name : Email: View Answer

20.	What is Weak Entity set?
	Answer: An entity set may not have sufficient attributes to form a primary key, and its primary key compromises of its partial key and primary key of its parent entity, then it is said to be Weak Entity set. Workspace Report errors ... Name : Email: View Answer