Explain what is aggregation, Database Management System

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.

Posted Date: 5/11/2013 2:16:49 AM | Location : United States







Related Discussions:- Explain what is aggregation, Assignment Help, Ask Question on Explain what is aggregation, Get Answer, Expert's Help, Explain what is aggregation Discussions

Write discussion on Explain what is aggregation
Your posts are moderated
Related Questions
let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Backward Recovery (UNDO): In this system the uncommitted changes made by a transaction to a database are undone.  Instead the system is reset to the last consistent state of databa

What is a guard condition? Explain it with a suitable example. The guard-condition is a Boolean expression written with respect to parameters of triggering event and attributes

With the help of an example display how records can be deleted and updated in QBE. (i) Increase Pay_Rate of employees along with the skill of ‘cook' by 10%. (ii) Delete employee

tell me the functionality,advantages and disadvantages of student database

Consider the join of a relation R with relation S. If R has m tuples and S has n tuples, then the maximum size of join is: If R has m tuples and S has n tuples then maximum siz

Consider the E/R schema with weak entity sets shown below. Come up with the SQL CREATE TABLE statements (with appropriate primary key, unique and foreign key constraints). Include


Design a generalization–specialization hierarchy for a motor-vehicle sales company. The company sells motorcycles, passenger cars, vans, and buses. Justify your placement of attrib

What is hash file organization? What are the causes of bucket overflow within a hash file organization? What can be completed to decrease the occurrence of bucket overflow?