Explain what is aggregation, Database Management System

Assignment Help:

Explain what is Aggregation ?

Aggregation: This is used whenever we intend to show a relationship between an entity and the relationship. There is no provision for this in the ER Model. This is shown by placing the relationship between two entities along with the entities in a box and setting up a relationship between this box and another entity.


Related Discussions:- Explain what is aggregation

Define the query optimisation, Define the Query optimisation The query ...

Define the Query optimisation The query parser commonly generates a standard initial tree to correspond to an SQL query, with no doing any optimization. Such type of a canonica

Give the levels of data abstraction, Give the levels of data abstraction? ...

Give the levels of data abstraction? There are three levels of Data Abstraction a) Physical level b) logical level c) view level

What is the difference between primary key and a unique key, What's the dif...

What's the difference between a primary key and a unique key? Both primary key and unique key enforces uniqueness of the column on which they are explained. But by default prim

Database, A database has been designed for this beauty parlour in order for...

A database has been designed for this beauty parlour in order for the staff to manage specific things such as bookings made by clients, payments, staff availability, level of exper

Objectives-file organisation in dbms, Objectives  After reading this un...

Objectives  After reading this unit you should be able to: Explain storage of databases on hard disks; Discuss the execution of various file Organisation techniques;

Indexed (indexed sequential) file organisation, Indexed (Indexed Sequential...

Indexed (Indexed Sequential) File Organisation It organises the file like a big dictionary, i.e., records are kept in order of the key but an index is stored which also allows

What is relationship, What is relationship? Give examples A relationshi...

What is relationship? Give examples A relationship is an association between several entities. Example: A depositor relationship associates a customer with every account tha

What does data dictionary is a special file contains, What does data dictio...

What does data dictionary is a special file contains ? The data dictionary is a special file contain The name of all fields in all files.The width of all fields in all files an

Durability-transaction , Durability : This property necessitates that once ...

Durability : This property necessitates that once a transaction has committed, the changes made by it be never lost because of subsequent failure. Thus, a transaction is also a bas

Name the three major database in oracle, Name the three major set of files ...

Name the three major set of files on disk that compose a database in Oracle. There are three main sets of files on disk that compose a database. All the files are binary. These

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