Strong entity set and weak entity set, Database Management System

Assignment Help:

Strong entity set and weak entity set?

Strong entity set and weak entity set: A strong entity set has a primary key. All tuples in the set are distinguishable through that key. A weak entity set has no primary key unless attributes of the strong entity set on that it depends are involved. Tuples in a weak entity set are partitioned according to their relationship along with tuples within a strong entity set. Tuples within each partition are distinguishable through a discriminator that is a set of attributes. A strong entity set has a primary key. All tuples in the set are distinguishable through that key. A weak entity set has no primary key unless attributes of the strong entity set on that it depends are included. Tuples in a weak entity set are partitioned according to their relationship along with tuples in a strong entity set. Tuples within every partition are distinguishable through a discriminator, which is a set of attributes.


Related Discussions:- Strong entity set and weak entity set

Relational database, Convert the following ER - diagram (Entity Relationsh...

Convert the following ER - diagram (Entity Relationship Diagram) into a relational database (the primary keys are underlined): 2160_Convert the following ER - diagram into a

Design an algorithm to implement operations, Design an algorithm to impleme...

Design an algorithm to implement operations  Each and every operation specified in the functional model could be formulated as an algorithm. The algorithm indicates how operat

Describe the most important classes of parallel machines, Question 1 Discu...

Question 1 Discuss the classification of DBMS based on location of database Question 2 Explain with examples different SQL commands used for creating and deleting relations.

Foreign keys , Foreign Keys and NULL Let us take the relation:         ...

Foreign Keys and NULL Let us take the relation:                 DEPT DEPT ID DNAME BUDGET D1 M

ER DIAGRAM, NEED ER DIAGRAM WITH MINIMUM ENTITY AND RELATIONSHIP of Hospita...

NEED ER DIAGRAM WITH MINIMUM ENTITY AND RELATIONSHIP of Hospital Management System

Security-drawbacks of data distribution, Security: In a centralised system...

Security: In a centralised system, access to the data can be simply controlled. Though, in a distributed DBMS not only does access to replicated data have to be controlled in many

What is a dataset, What is a dataset? A dataset is an in-memory databas...

What is a dataset? A dataset is an in-memory database that is disconnected from any regular database, but has all the significant characteristics of a regular database. Dataset

What are the key features of oracle, What are the key features of Oracle? ...

What are the key features of Oracle? Key features of Oracle are as follows: • Read Consistency • Concurrency • Locking Mechanisms • Quiesce Database • RAC • Portability

Compute the closure set, Compute the closure (F+) for the following set of ...

Compute the closure (F+) for the following set of the functional dependencies defined on R(a,b,c,d), where F - {c→ a, ab → d, a → b, d → c}, i.e. what are all of the FDs implied b

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