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

Each statement should have a where clause, Submit SQL SELECT Statements to ...

Submit SQL SELECT Statements to demonstrate several reports off your database, according to the following guidelines: You must submit at least 5 SELECT Statements. Each

What are the two integrity rules, What are the two integrity rules?  An...

What are the two integrity rules?  Ans:  The two integrity rules are: Entity Integrity Rule & Referential Integrity Rule.   Entity Integrity Rule - If the attribute A of rel

Define view? how it is related to data independence, A View may be defi...

A View may be defined of as a virtual table, that is, a table that does not really exist in its own right but is instead inferred from one or more underlying base data table. T

Database administrator, Database Administrator One of the main perpos...

Database Administrator One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having li

Mobile database, write short note on mobile database

write short note on mobile database

What are advantages of using an index and disadvantages, What are the advan...

What are the advantages of by using an index and what are its disadvantages ? In difference, if the search key of a secondary index is not a candidate key, it is not sufficient

What is the difference between where and having clauses, What is the differ...

What is the difference between WHERE and HAVING clauses?. Predicates in the WHERE clause applies to every tuple while the predicate in the HAVING clause applies to groups.

Explain the equijoin, Explain the θ-join and equijoin Refer tables Car ...

Explain the θ-join and equijoin Refer tables Car and Boat which list models of cars and boats and their relevant prices. Assume a customer wants to buy a car and a boat, but sh

Explain hash file organization, Explain hash file organization? Hash fu...

Explain hash file organization? Hash functions a) The distribution is uniform Hash functions assign each bucket the similar number of search -key values from the set of a

Prepare heart failure registry database, Prepare Heart Failure Registry dat...

Prepare Heart Failure Registry database How are you today? Please I would like you to design a Heart Failure registry where doctors will log in to enter information about their

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