Ordering of tuples, Database Management System

Assignment Help:

In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later according to some attribute value in the storage systems. For instance, records in PERSON table may be structured according to PERSON_ID. Such organisation or data depends on the requirement of the underlying database application. Though, for the purpose of display we may get them displayed in the sorted order of age. The following table is sorted by age. It is also worth states here that relational model does not permit duplicate tuples

PERSON

PERSON_ID      NAME                                 AGE              ADDRESS

2                           Sharad Gupta                       33                  Pocket 2, Mayur Vihar.

1                           Sanjay Prasad                      35                  b-4,Modi Nagar

3                           Vibhu Datt                           36                  c-2, New Delhi

Super Keys, Candidate Keys and Primary Keys for the Relations

As discussed in the last section ordering of relations does not matter and all tuples in a relation are unique. Though, can we uniquely recognize a tuple in a relation? Let us talk about the concepts of keys that are primarily used for the purpose as above.


Related Discussions:- Ordering of tuples

Define the terms entity, Define the terms entity, attribute, role and relat...

Define the terms entity, attribute, role and relationship between the entities, giving examples for each of them.         Ans: Entity:   An entity is a "thing" or "object" in th

Query optimization in database system, Problem : AirwaysCentre, an inte...

Problem : AirwaysCentre, an international airline booking company currently uses a relational database system for their operations, which includes the following relations: P

Many-to-many relationship, For each m:n relationship type R, we make a new ...

For each m:n relationship type R, we make a new table (say S) to represent R. We also contain the primary key attributes of both the participating entity types as a foreign key att

Remove partial dependancy, , write the relational schema, and draw the new ...

, write the relational schema, and draw the new dependency diagrams. Identify the normal forms for each table structure you created

Data storage and retrieval services, An Enterprising group of Entrepreneurs...

An Enterprising group of Entrepreneurs introduced a new business named StoreItRite which is based on data storage and retrieval services. It provides the services and the company c

List the types of authorization, List the types of authorization. A) R...

List the types of authorization. A) Read authorization B) Write authorization C) Update authorization D) Drop authorization

State the rearranging the execution order for efficiency, Define the step -...

Define the step - Rearranging the Execution Order for Efficiency As we know that algorithm and data structure are closely related to one another, but data structure is conside

What is called block-level striping, What is called block-level striping? ...

What is called block-level striping? Block level striping stripes blocks across many disks. It treats the array of disks as a large disk, and provides blocks logical numbers

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