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

Explain the term high level dml, Explain the term High level DML? High...

Explain the term High level DML? High level DML A high-level or non-procedural DML permit the user to specify what data is needed without specifying how it is to be acquired.

How can you start mysql server, How can you Start MySQL Server? To star...

How can you Start MySQL Server? To start the mysql program type it is name in the command- line prompt. After starting mysql program just display A welcome letter using the

What are stand-alone procedures, What are stand-alone procedures? Proce...

What are stand-alone procedures? Procedures that are not part of a package are called as stand-alone because they independently defined. A good example of a stand-alone procedu

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

What is a view? How it is related to data independence? A view might be thought of as a virtual table, that is, a table that does not really exist in its own right but is inste

Define first normal form and second normal form, First Normal Form and seco...

First Normal Form and second normal form First Normal Form (1NF) A relation is said to be in 1NF if it having no non-atomic values and each row can give a unique combinat

Explain domain calculus, Explain Domain calculus Domain calculus is one...

Explain Domain calculus Domain calculus is one of the types of the relational calculus. The formal specification of the domain calculus was planned after the development of the

When it is better to use files than a dbms, When It is better to use files ...

When It is better to use files than a DBMS? It is better to use files than a DBMS when Multiple users wish to access the data.

Define normalization, Normalization :It is a process of examine the given ...

Normalization :It is a process of examine the given relation schemas based on their primary key and Functional Dependencies (FDs) to achieve the properties Minimizing redun

Write short note on events, Write short note on Events Events consist ...

Write short note on Events Events consist of inputs, interrupts, decisions and actions performed by any external device or users. Every event always has a sender and receiver.

Explain discretionary access control, Problem: (a) Given the following ...

Problem: (a) Given the following relation: Stats(Name,Sex,Children, Occupation, Salary, Tax, Audits) Write SQL code to define the following security constraints: (i) User

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