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

Relational declarative database language environment, Server Control It ...

Server Control It is usual to control access to the data via the front end application, for example by displaying data as ‘read only'. This part of the assignment illustrates ho

Database ass1, #quCreate a database design specification (Enhanced Entity R...

#quCreate a database design specification (Enhanced Entity Relationship Diagram (EERD) and Relational Data Model (RDM)) from the given business description. The RDM must be in 3rd

Relational algebra and calculus, Q.  What is relational algebra and calcul...

Q.  What is relational algebra and calculus? Explain the relational algebra operators :- Selection and predicate, set operation, joins and division. Sol. Relational Algebra

Define raid structure, Define raid? Briefly explain it? A range of disk...

Define raid? Briefly explain it? A range of disk organization methods, collectively called redundant arrays of independent disks (RAID) o   Improvement of reliability throug

Explain data sublangauges, Explain Data Sublangauges ? Data sublanguage...

Explain Data Sublangauges ? Data sublanguage: In relational database theory, the term sublanguage, first used for this purpose through E. F. Codd in the year of 1970, refers t

What are called jukebox systems, What are called jukebox systems? Jukeb...

What are called jukebox systems? Jukebox systems have a few drives and numerous disks that can be loaded into single of the drives automatically.

Which data manipulation command combines the records, Which data manipulati...

Which data manipulation command combines the records from one or more tables ? JOIN data manipulation command combines the records from one or more tables.

Example of grant create session to mca12, Example -GRANT CREATE SESSION TO ...

Example -GRANT CREATE SESSION TO MCA12; (This command gives system level permission on creating a session - not portable) GRANT SELECT ON EMP TO MCA12; (Object level permi

Reflects organisational structure, Reflects organisational structure: Many ...

Reflects organisational structure: Many organizations are distributed over various locations. If an organisation has many offices in dissimilar cities, databases used in such an ap

Functional dependencies, 1. Staff (staffID --> availabilityID) 2. Servic...

1. Staff (staffID --> availabilityID) 2. Services (servicesID --> itemBasedID --> timedBasedID) 3. TimedBased (timedbasedID--> priceid) 4. Clients (clientId, serviceId-->

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