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

Determine the subsystem design issue, Determine the Other System Design Iss...

Determine the Other System Design Issue How to realise subsystems; through hardware or software? How is object model mapped on chosen hardware software? Mapping

Define the concept of design documentation, Design Documentation  The ...

Design Documentation  The Design Document shall be an extension of Requirements Analysis Design. "The Design Document will comprise a revised and much more detailed descrip

Explain the uses of deadlock, Explain the uses of deadlock It will lea...

Explain the uses of deadlock It will lead to deadlock since this is the only place where incoming acknowledgements are processed. Without this code, sender will keep timing ou

Advantages and drawbacks of ddbms, Advantages And Drawbacks Of Ddbms  T...

Advantages And Drawbacks Of Ddbms  There are various reasons for building distributed database systems, with sharing of data, reliability and availability, and speedup of query

Convert the er - diagram into a relational database, Convert the following ...

Convert the following ER - diagram (Entity Relationship Diagram) into a relational database (the primary keys are underlined):       Ans:  The relational database schema f

What is conceptual model, What is conceptual model ? A conceptual model...

What is conceptual model ? A conceptual model is a independent of both hardware and software.

Write a program within embedded sql to associative relation, Write a progra...

Write a program within embedded SQL to associative the total trip expenses of the salesman named ‘John' for the relations. EXEC SQL BEGIN DECLARE SECTION; long total_expenses;

Mention the purpose of sid and sod lines, Mention the purpose of SID and SO...

Mention the purpose of SID and SOD lines SID (Serial input data line): It is an input line by which the microprocessor accepts serial data. SOD (Serial output data line)

What is rdbms, What is RDBMS? Relational Data Base Management Systems (...

What is RDBMS? Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be formed and

What is a checkpoint, What is a checkpoint? List the operations to be perfo...

What is a checkpoint? List the operations to be performed by the system when a checkpoint is to be taken. What does the recovery system do if there is a crash? There is large n

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