What is completeness constraint on generalization, Database Management System

Assignment Help:

What is completeness constraint on generalization? Define the variation between total and partial design constraint. Give an example each.    

 Ans: Completeness Constraints 

1. Total specialization  constraint

a. Each entity in the superclass should be a member of some subclass in the specialization for example {HOURLY_EMPLOYEE, SALARIED_EMPLOYEE} 

b. Notation: superclass 

2. Partial specialization constraint an entity might not belong to any type of the subclasses 

For example: {SECRETARY, ENGINEER, TECHNICIAN}


Related Discussions:- What is completeness constraint on generalization

What is catalog in dbms, What is catalog in DBMS? Catalog - A relationa...

What is catalog in DBMS? Catalog - A relational DBMS maintains information about every table and index in which it contains. A catalog is a collection of special tables that st

What is sql profiler, What is SQL Profiler? SQL Profiler is a graphical...

What is SQL Profiler? SQL Profiler is a graphical tool that permits system administrators to monitor events in an instance of Microsoft SQL Server. You can capture and save dat

Update operations, The Update Operations : Update operations are used fo...

The Update Operations : Update operations are used for altering database values. The constraint violations faced by this operation are logically the similar as the problem faced

The proliferation of object-oriented methods, The Proliferation of Object-O...

The Proliferation of Object-Oriented Methods The first few years of the 1990s saw blossoming of around fifty various object oriented methods. This proliferation is a sign of g

Explain the project-join normal form, Explain the Project-Join normal form ...

Explain the Project-Join normal form A relation R is in PJNF along with respect to a set of functional dependencies D if for all join dependencies of the outline *(R 1 , R 2 ,

multiple-mode locks, Multiple-mode locks : It offers two locks: exclusive ...

Multiple-mode locks : It offers two locks: exclusive locks and shared locks. But why do we require these two locks? There are a lot of transactions in the database system that neve

Security and integrity, Security And Integrity After Reading the concep...

Security And Integrity After Reading the concepts of database recovery in the last section, let us now deal with a vital concept that helps in minimizing consistency errors in

Need website hacking security test, We want have a website; we need to test...

We want have a website; we need to test the security of our website. You need to: -Try to bypass our security by simulate a website hacking -Try some hack Techniques like

Describe the terms ‘database'' and ‘data warehouse'', Problem: ‘Users a...

Problem: ‘Users and Information system specialists need to spend inordinate amounts of time locating and gathering data' (Watson and Hal, 1998) Recent developments in the ar

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd