Describe the concept of aggregation, Database Management System

Assignment Help:

Aggregation

Aggregation is stronger form of association. It represents the "has-a" or "part-of" relationship. An aggregation association depicts a complex object which is composed of other objects. You can characterize a house as a combination of its roof, floors, walls, foundation, windows, and rooms and so on. A room may in turn be, composed of walls, floor, ceiling, doors and windows, as shown in Figure.

In UML, a link is placed among the "whole" and "parts" classes, with a diamond head (Figure) attached   to the complete class to indicate which association is   an aggregation. Multiplicity can be   precise   at the end of the association for each of   "part-of" classes to indicate constituent parts. The method of decomposing a complex object into its component objects can be extended until desired level of detail is reached.

1159_aggregation.png

          Figure: A house and some of its component


Related Discussions:- Describe the concept of aggregation

Explain the internal architecture of 8086, Problem 1. Write an assembly...

Problem 1. Write an assembly program to find the smallest among two numbers Writing an assembly program to find the smallest among two numbers 2. Explain the intern

Write short note on data models, Write short note on Data models? Data...

Write short note on Data models? Data models: A data model is an abstract model which elaborates how data is represented and accessed. The term data model has two commonly ac

What are advantages of object models, What are advantages of object models?...

What are advantages of object models? Object models are efficient for communicating with the application experts and reaching a consensus about the significant aspects of the p

What is magnetic disks, What is magnetic disks?explain it? Magnetic dis...

What is magnetic disks?explain it? Magnetic disk provides the bulk of secondary storage of modern computer system. The disk capacity is growing at over 50% per year. But the st

Define the two phase locking protocol, Define the Two Phase Locking Protoco...

Define the Two Phase Locking Protocol This is a protocol that is used to make sure serializability of transactions. This protocol needs that every transaction issue lock and u

State the steps of object design, State the Steps of Object Design ...

State the Steps of Object Design Object design is a very iterative process in which various classes, relationships among objects are added when you move from one level to

Domains, Every simple attribute of an entity type have a possible set of va...

Every simple attribute of an entity type have a possible set of values that can be attached to it. This is known as the domain of an attribute. An attribute cannot have a value out

Data Analysis, A buyer for a large department store chain must place orders...

A buyer for a large department store chain must place orders with an athletic shoe manufacturer six months prior to the time the shoes will be sold in the department stores. In par

Develop motel point of sale software, Project Description: I need a poin...

Project Description: I need a point of sale for motels. It needs to run on windows and requires being network able so that we can have more than one computer using it at once.

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