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

Query processor in database management system, Query Processor The qu...

Query Processor The query language processor is responsible for taking query language statements or shifting them from the English-like syntax of the query language to a form

Create a table for database transformation , Step 1 . Using Oracle, create ...

Step 1 . Using Oracle, create the tables identified in the preferred solution for Assignment 2. Technicians (ZipCode, TechnicianID, FirstName, LastName, Street, City, State, Home

Which is the properties of entities, Which is the properties of entities? ...

Which is the properties of entities? Attributes is the properties of entities.

Update operations in dbms - insert operation, Update Operations and Dealing...

Update Operations and Dealing with Constraint Violations There are three basic operations to be executes on relations: Insertion Deletion Update The INSER

What are the advantages of object oriented databases, What are the advantag...

What are the advantages of object oriented databases in comparison with others? Why it is still not widely used? Object oriented designs are coherent, efficient and less prone

Explain the difference between drop and delete, Explain the Difference betw...

Explain the Difference between DROP and DELETE DELETE deletes one or more than one tuples of a particular relation from the database. DROP is employed to remove a table from th

Scope of traffic data management, A TDMS project plan is not a typical Info...

A TDMS project plan is not a typical Information Technology project plan; therefore, a traffic data project has several unique characteristics: Traffic data management system

What are stored-procedures, What are stored-procedures? And what are the ad...

What are stored-procedures? And what are the advantages of using them? Stored procedures are database objects that perform a user defined operation. A stored procedure can have

What do you mean by atomicity and aggregation, What do you mean by atomicit...

What do you mean by atomicity and aggregation? Atomicity : Either all actions are carried out or none are. Users should not have to worry about the effect of incomplete trans

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