Explain weak and strong entity type, Database Management System

Assignment Help:

Explain weak and strong entity type ?

Weak and Strong entity type: An entity set which does not have a primary key is referred to as a weak entity set. The existence of a weak entity set depends on the existence of a strong entity set; it must associate to the strong set via a on-to-many relationship set. A discriminator of a weak entity set is the set of attributes that distinguishes between all the entities of a weak entity set. The primary key of a weak entity set is formed by the primary key of the strong entity set on that the weak entity set is existence depends, plus the weak entity set's discriminator.


Related Discussions:- Explain weak and strong entity type

Explain current page table and shadow page table, Explain current page tabl...

Explain current page table and shadow page table. The key idea behind the shadow paging method is to maintain two page tables during the life of the transaction: the current pa

What is meant by heuristic optimisation, What is meant by heuristic optimis...

What is meant by heuristic optimisation?  Discuss the main heuristics that are applied during query optimisation.  Ans:  In heuristic optimization, heuristics are employed to r

Process-oriented decompositions, Process-oriented decompositions Pr...

Process-oriented decompositions Process-oriented decompositions divide complex process, task or function into simpler sub processes until they get simple enough to be deal

Explain nested relations, Explain nested relations? Nested relations ...

Explain nested relations? Nested relations The assumption of INF is a natural one in the bank examples we have considered. However, not all applications are best modelled

Develop a database design , A practice called Perfect Pets provides private...

A practice called Perfect Pets provides private health care for domestic pets throughout America. This service is provided through various clinics located in the main cities of Ame

Using sql create a view rs for the relations r and s, Using SQL create a vi...

Using SQL create a view RS for the relations R and S. The view consists of the columns A and D renamed as X and Y in that order. Insert a tuple into it. Show the contents of t

Urgent need tutoring in conjunction with help on assignment!, Hi is anyone ...

Hi is anyone well versed in accounting information systems available now to help me work through an important assignment due tomorrow at noon?

Data aggregation, Q.   Explain  data aggregatio n and discuss differen...

Q.   Explain  data aggregatio n and discuss different design constraints. Sol. Aggregation   One limitation of the E-R model is that it cannot express relationships amon

Perform an exploratory analysis on the entire dataset, Australian Bureau of...

Australian Bureau of Statistics (ABS) provides retail data for different groups and different states as well as the aggregate numbers. Table 11 " Retail Turnover, State by Industry

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