Participation constraints, Database Management System

Assignment Help:

The participation Constraints shows whether the existence of an entity depends on its being associated to another entity by the relationship type. There are two kinds of participation constraints:

Total: When the entire entities from an entity set participate in a relationship type, is known as total participation, for instance, the participation of the entity set student in the relationship set have to 'opts' is said to be total as each student enrolled must opt for a course.

Partial: When it is not necessary for all the entities from an entity set to partake in a relationship type, it is known as partial participation. For instance, the participation of the entity set student in 'represents' is partial, as not every student in a class is a class representative.


Related Discussions:- Participation constraints

Query optimization, what is meant semantic query optimization? how does it ...

what is meant semantic query optimization? how does it differ from other query optimization techniques?

Need website hacking security test, We want have a website; we need to test...

We want have a website; we need to test the security of our website. You need to: -Try to bypass our security by simulate a website hacking -Try some hack Techniques like

Max. no. of structures in a table or structure, What is the max. no. Of str...

What is the max. no. Of structures that can be included in a table or structure. Nine.

Increased overheads on update-data replication, Increased overheads on upda...

Increased overheads on update : On the drawbacks side, it will need the system to ensure that all replicas of a relation are consistent. This shows that all the replicas of the rel

Determine bcnf-dcnf and key relation, (A) For the relation; CarSales (R...

(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg

Three level architecture of dbms-logical architecture, Three Level Architec...

Three Level Architecture of DBMS or Logical DBMS Architecture The logical architecture defines how data in the database is perceived by users. It is not deals with how the da

Components of database manager, Components of database manager The ab...

Components of database manager The above functions are reached by the database manager. The major elements of a database manager are: Authorisation control: This mod

What do you understand by acid, What do you understand by ACID? - ACID...

What do you understand by ACID? - ACID (Atomicity Consistency Isolation Durability) is a quality sought after in a reliable database. Here's the relevance of each quality:

State the object design for processing, State the Object Design for Process...

State the Object Design for Processing  The object design phase comes after analysis and system design phase. The object design phase includes implementation details like as i

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