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 are referential integrity constraints, What are referential integrity ...

What are referential integrity constraints? A value that appears in single relation for a given set of attributes also appears for a particular set of attributes in another rel

When is a transaction rolled back, When is a transaction rolled back? A...

When is a transaction rolled back? Any changes that the aborted transaction made to the database must be uncompleted. While the changes caused by an aborted transaction have be

Managing database, 10A.53 Code an Oracle Database trigger to enforce the ...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

Problem about data mining for business intelligence, Do the 11.1 11.1 Cre...

Do the 11.1 11.1 Credit Card Use. Consider the following hypothetical bank data on consumers’ use of credit card credit facilities in Table 11.3. Create a small worksheet in Exce

Discuss difference between drop table r and delete from r, Discuss The diff...

Discuss The difference between drop table R and delete from R.  DROP TABLE command deletes all the records with the table definition. This command will automatically committed

The concurrent transactions, The Concurrent Transactions  Almost every ...

The Concurrent Transactions  Almost every commercial DBMS support multi-user environment. Therefore, allowing multiple transactions to proceed concurrently. The DBMS must make

Compare the two log based recovery schemes, Compare the two log-based recov...

Compare the two log-based recovery schemes in terms of ease of implementation and overhead cost.    Ans:  There are two types of log based recovery techniques: deferred update

Type of views-data control, Type of views :  Simple views and Difficult ...

Type of views :  Simple views and Difficult Views Feature Simple Views Complex Views Number of tables One

Explain the disadvantages of creating a temporary table, Explain the disadv...

Explain the disadvantages of creating a temporary table? If you have already created a temporary table with a shown name and attempting to create a second one with that nam

Explain the two types of participation constraint, Explain the two types of...

Explain the two types of participation constraint.  Total: The participation of an entity set E in a relationship set R is said to be total if each entity in E participates i

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