Relation and relational schema, Database Management System

Assignment Help:

A relation has:

  • Relational Schema
  • Relation instance

Relational Schema:

A relational schema shows the relation's name, its attributes and the domain of every attribute. If R is the name of a relation and A1, A2...An is a list of attributes showing R then R (A1, A2...An) is known as a relational schema. Every attribute in this relational schema takes a value from some explicit domain called Domain (Ai).

For instance, the relational schema for relation PERSON as in Figure will be: PERSON (PERSON_ID:integer, NAME: string, AGE:integer, ADDRESS:string)

Total number of attributes in a relation indicates the degree of a relation. Hence the

PERSON relation includes four attributes, so this relation is of degree 4


Related Discussions:- Relation and relational schema

Function module, When a function module is activated syntax checking is per...

When a function module is activated syntax checking is performed automatically. YEs, a function module is activated syntax checking.

Datawarehouse, How to define a job scheduling strategy that will meet busin...

How to define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a

Er database theoretical and modeling database system, Need an expert in ER ...

Need an expert in ER database theoretical and modeling database system Project Description: Need an expert in ER database theoretical and modeling database systems? Skills

Describe the concepts of structural semantic data model, Question 1 List a...

Question 1 List and explain various Normal Forms. How BCNF differs from the Third Normal Form and 4th Normal forms? Question 2 Describe the concepts of Structural Semantic Da

Concurrency executions, Explain TPS concurreny executions stating their adv...

Explain TPS concurreny executions stating their advantages in online business advancement

Hangman, a method named WonGame that checks each letter in the word is matc...

a method named WonGame that checks each letter in the word is matched by its label

Explain derived and non-derived attribute, Explain Derived and Non-Derived ...

Explain Derived and Non-Derived Attribute? In few cases, two or more attribute values are related, for instance, Age and BirthDate attributes of a person. For specific person e

Define assertions in sql, Define Assertions in SQL a. An assertion is a...

Define Assertions in SQL a. An assertion is a predicate that is expressing a condition we wish the database to always satisfy.  b. Domain constraints, functional dependency

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

What is the disadvantage of a call by reference, What is the disadvantage o...

What is the disadvantage of a call by reference? During a call by reference damage or loss of data is not restricted to the subroutine, but will instantly lead to alters to th

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