Aggregation in object oriented programming
Published: 2023-06-07 05:19:13

Object-oriented software development is an approach to programming in which objects represent data and behavior. 

[Aggregation in DBMS](https://www.codingninjas.com/codestudio/library/generalization-specialization-and-aggregation-in-dbms) is a fundamental notion in the object-oriented programming language that allows a single object to hold a collection of copies of a different object. 

This process comes in handy when the programmer requires to store several objects that belong to the same class. One of the most appropriate examples used for explaining aggregation is the collection of parts of a car. For instance, you can store separate classes within a program for the engine, tyers, and other car parts. 

In this article, we will look at the notion of aggregation as well as its applications in the area of object-oriented programming.

What is Aggregation in a Database Management System?

Aggregation is a type of connection in which one item, the package or parent thing, includes a number of versions of another object, the entailed or child object. 

The "has-a" connection can be used to indicate aggregation, whereby the package object "has-a" corresponds to the enclosed object.

Consider the scenario of an automobile and its combustion chamber to grasp the notion of aggregation better. 

An automobile is composed of several different components, the largest of which is the vehicle's engine. A combustion engine is an independent unit that delivers energy to the car and thus is a crucial component of its operation. 

In this example, the car may be considered a package object while the engine is enclosed. Because the vehicle "has-a" connection to the combustion engine, it is a representation of aggregation.

In the field of object-oriented programming, aggregation may be achieved through several strategies, such as composing and delegating. The package object generates and controls the contained entity in composition, but the body of the container item forwards the enclosed entity in question.

With that said, it might help to understand the process of aggregation better by having a step-by-step analysis of how the program is executed. 

Look at the next segment of the blog, where we explain the process of aggregation in DBMS.

How to perform aggregation in DBMS?


Here's a prime instance of how aggregation can be implemented in the framework of object-oriented programming:


Construct the "part" class in the following manner: Create the class which defines a "part" that makes up the aggregation first. If you're constructing an aggregation amongst a car with its wheels, for instance, the "part" class will correspond to the Wheel class.

Define the term "whole": Construct the class which corresponds to the "whole" component of an aggregation. A few occurrences of the "part" category will be present in this class. For instance, if you're aggregating a vehicle, including its tires, the "whole" class will be Car.

Create a "part" object instance within the "whole" object: Make a component of the "part" object within the "whole" class. For instance, you may generate four variations using the Wheel class within the Car class to represent the vehicle's four wheels.

Methods should be utilized for exposing the "part" class examples: Create methods within the "whole" class which provide access to objects of the "part" object. Within the Car class, as an example, developers can define a function named getWheels() which provides an array containing the four Wheel objects.


Basically, these are the few steps involved in performing aggregation in DBMS. There are several advantages of using aggregation while compiling a program. Check them out in the next segment of the blog.


What are the advantages of using Aggregation?


The process of aggregation proves to be highly fundamental if you are deciding upon file vs DBMS. One of the advantages of using aggregation is the fact that it helps in the organization of data. 

Have a look at an in-depth analysis of the advantages of aggregation.


One of the major benefits of aggregation has to do with how it enables improved code organization and encapsulation. By breaking down intricate functionality through components that are more manageable in size, the source code gets easier to comprehend and manage. Aggregation also provides for the reuse of code by allowing enclosed objects to be reused across numerous container objects.

Another benefit of aggregation would be that it supports polymorphism, as well as an object's capacity to take on various configurations. Because an object in a container can house any item that follows the same protocol or derives from an identical class, this is feasible. Assume an object as a container that houses several types of mammals. It can hold representations of numerous mammal classes which implement identical interfaces.

Aggregation can also be used to create systems that demand flexibility and adaptability. By breaking down complexity into smaller pieces, it becomes easy to add or delete components as needed by the system. Furthermore, aggregation enables an open relationship between items, which implies that modifications of one's characteristics do not affect the other.


However, there are several disadvantages to aggregation that must be addressed while developing a system. 

The aggregation has the severe disadvantage of increasing the total number of items in the framework, which may lead to performance concerns. Furthermore, poor aggregate utilization might result in code complexity, which makes it harder to comprehend and uphold the codebase.

An additional issue of aggregation in DBMS is how it might result in loop dependencies, which are situations in which multiple entities rely on one other, culminating in a stalemate. Loop dependencies could be avoided by adhering to ethical design practices and verifying that the items are designed in a manner that they are not dependent on one another.


**Final Thoughts **


In the field of object-oriented programming, aggregating is a handy idea that enables one object to include a number of instances from another object. This leaves no room for confusion for the programmers to decide upon [file vs DBMS](https://www.codingninjas.com/codestudio/library/dbms-vs-rdbms-and-dbms-vs-file-system)

Aggregation provides various advantages, including improved code organization and encapsulation, repetition of code, variation, flexibility, and scalability. 

Yet, it has some drawbacks, including a boost in the total quantity of entities in the framework, increased code intricacy, and loop dependencies. 

In order to prevent these concerns, it is critical to employ aggregation sparingly and adhere to conventional design practices.