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 segments in oracle, What are segments in oracle? Segments - Ea...

What are segments in oracle? Segments - Each table has single field of disk space, known as segment, set aside for it in the tablespace. Segments consist of contiguous sections

What is an operand, What is an Operand? The data on which the operation...

What is an Operand? The data on which the operation is to be performed is known as an Operand

Product adder required for ecommerce website, Product adder required for Ec...

Product adder required for Ecommerce website Project Description: Want a product adder for 500 products I have a magento website and need products pulled from site A to my si

Ways to suggest the dba, a)  Suppose we updated the catalog tables in real ...

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few

Consistency error-database errors, Consistency error : These errors happen ...

Consistency error : These errors happen due to the inconsistent state of database caused may be due to wrong implementation of commands or in case of a transaction abort.  To overc

Hass, waht is a repeating group?

waht is a repeating group?

What is the difference between a key and a superkey, What is the difference...

What is the difference between a key and a superkey? Key - A key a single attribute or a combination of two or more attributes of an entity set which is used to identify one

Maping constraits, #question.what is mapping constraints and types?.

#question.what is mapping constraints and types?.

File organisation and its types, File Organisation And Its Types  Just ...

File Organisation And Its Types  Just as arrays, trees, lists and other data structures are used to execute data Organisation in main memory, a number of planning's are used to

What is deadlock, What is deadlock? How can it be avoided? How can it be re...

What is deadlock? How can it be avoided? How can it be resolved once it occurs? Deadlock happens when two transactions are each waiting on a resource that the other transaction

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