Domain constraints, Database Management System

Assignment Help:

Domain Constraints

Domain constraints are primarily formed for defining the logically correct values for an attribute of a relation. The relation allows attributes of a relation to be confined to a range of values, for instance, values of an attribute age can be restricted as Zero to 150 or a definite type like integers, etc.

                                                      REDUNDANCY AND ASSOCIATED PROBLEMS

Let us take the subsequent relation STUDENT

Enrolment no

Sname

Address

Cno

Cname

Instructor

Office

050112345

Rahul

D-27, main Road

Ranchi

MCS-011

Problem

Solution

Nayan

Kumar

102

050112345

Rahul

D-27, Main Road

Ranchi

MCS-012

Computer

Organisation

Anurag

Sharma

105

050112345

Rahul

D-27, Main Road

Ranchi

MCS-014

SSAD

Preeti

Anand

103

050111341

Aparna

B-III, Gurgaon

MCS-014

SSAD

Preeti

Anand

103

                                                                           Figure: A state of STUDENT relation

The above relation satisfies the properties of a relation and is said to be in first normal form (or 1NF). Theoretically it is convenient to have all the information in one relation as it is then likely to be simpler to query the database. But the relation over has the following undesirable kinds:


Related Discussions:- Domain constraints

What are the reasons for having variable length records, What are the reaso...

What are the reasons for having variable length records? What are the various ways to store variable length records? Variable-length records arise in a database in various wa

Design and building a distributed information system, The scenario You ...

The scenario You have been approached to design and implement a prototype of a distributed information system for a national car part retail outlet chain. The company comprises

aggregate functions-data manipulation language, Aggregate functions ...

Aggregate functions Some of these functions are min, count, max, and avg. These functions help in getting consolidated information from a set of tuples. Example:

Give expression in tuple calculus and domain calculus, Consider the subsequ...

Consider the subsequent relation schemes:  Project (Project#, Project_name, chief_architect)  Employee (Emp#, Empname)  Assigned_To (Project#, Emp#)  Give expression i

ER model, coventions for displaying an ER schema as ER diagram

coventions for displaying an ER schema as ER diagram

When is update_statistics command used, When is UPDATE_STATISTICS command u...

When is UPDATE_STATISTICS command used? - When processing of large data is done, this command is used. - Whenever large number of modification, deletions or copy takes place

Explain record based logical models, Explain Record Based Logical Models? ...

Explain Record Based Logical Models? Record-Based logical Models: Also define data at the conceptual and view levels. Unlike object-oriented models, are used to state overall

Database Models, Benefits and Limitations od Data Models?

Benefits and Limitations od Data Models?

On laod, how to write a in a text and load it on mysql

how to write a in a text and load it on mysql

Incident report to the database, The Form input elements are:           ...

The Form input elements are:             Reporter name                                                text type input             Password

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