Relation instance or relation state, Database Management System

Assignment Help:

A relation instance indicates as r is a collection of tuples for a given relational schema at a exact point of time.

A relation state r of the relation schema R (A1,A2,..........AN), also denoted by r(R) is a set of n-tuples

r = {t1,t2,............tm}

Where each n-tuple is an ordered list of n values

t  =  1,v2,........, vn>

where every vi belongs to domain (Ai) or includes null values.

The relation schema is also known as  'intension' and relation state is also known as 'Extension'.


Related Discussions:- Relation instance or relation state

Write the sql queries using data manipulation language, Problem 1. Writ...

Problem 1. Write the SQL queries using Data Manipulation Language (DML) statements. Insert values into student table with field names using insert command Display the

Draw an erd for the above relational schema, The following relational datab...

The following relational database schema represents part of a simplified database used by a library: tblBook (BookID, Title, PublisherID, Category,Price) tblPublisher (Publishe

Can you scan double-sided documents and remove blank pages, Can you scan do...

Can you scan double-sided documents - and remove blank pages? Our software and imaging systems supports duplex scanning, at the same time scanning both sides of a page. Program

relationship with the owner entity, A database for the Service and Mainten...

A database for the Service and Maintenance (SM) section of a Computer sales and service Company has to be developed. SM gives after sales service to customers. SM branch has a numb

What are the types of reference, What are the types of reference?explain it...

What are the types of reference?explain it with suitable examples? Object oriented language given the ability to refer the object attribute of the type can be referred to the s

Explain the ansi sparc architecture, Explain the ANSI SPARC architecture ...

Explain the ANSI SPARC architecture The three-schema architecture is as well known as ANSI SPARC architecture. The aim of the three-schema architecture is to separate the user

Implement a cache simulator, You are required to program (in a high level l...

You are required to program (in a high level language such as C, C++, Java) and implement a cache simulator which will have the following inputs and outputs:- INPUTS

Distributed transaction atomic-consistent-isolated, A distributed transacti...

A distributed transaction consists of subtransactions that execute at different sites and access local DBMSs at those sites. For example, a distributed transaction that transfers m

How many types of data independence have, Types of data independence D...

Types of data independence Data independence can be classified into the following two types: Physical Data Independence: This means that for any change made in the physi

Key to represent relationship between tables is called, Key to represent re...

Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.

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