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 embedding sql statements, Question 1 Explain the functions of t...

Question 1 Explain the functions of the following Storage Manager Buffer Manager Transaction Manager 2 Discuss about system catalog in a relational DBMS 3

Define lock, Define lock? Lock is the most common used to execute the r...

Define lock? Lock is the most common used to execute the requirement is to permit a transaction to access a data item only if it is currently holding a lock on that item.

Write short notes on transaction state, Write short notes on transaction st...

Write short notes on transaction state? A transaction may not always complete its implementation successfully such a transaction is termed aborted A transaction must be in o

DBMS, to develop elrctronic database from manual forms

to develop elrctronic database from manual forms

Clinic, Need a sample of a clinic database relationships

Need a sample of a clinic database relationships

Explain the exec statement in sql, Explain the Exec statement in SQL An...

Explain the Exec statement in SQL Ans: Exec statement has the structure    EXEC SQL END-EXEC   Embeded SQl statements are of a form identical to non embedded SQL statem

Insertion anomaly-data redundancy, Insertion Anomaly: Inability to show ce...

Insertion Anomaly: Inability to show certain information-The primary key of the over relation be (enrolment number, Cno). Any new tuple to be inserted in the relation should have

What is rdbms terminology for a row, What is RDBMS terminology for a row? ...

What is RDBMS terminology for a row? A tuple is a RDBMS terminology for a row

What is null described testing for null in sql?, What is NULL? Give an exa...

What is NULL? Give an example to described testing for NULL in SQL? The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a re

Mysql database merge, MySQL Database Merge Project Description: I hav...

MySQL Database Merge Project Description: I have two databases, I need merge the data of one database into another Work to be done online right now. Payment can be done

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