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

Basic set operation, These are the binary operations; i.e., each is applied...

These are the binary operations; i.e., each is applied to two relations or sets. These two relations can be union compatible excluding in case of Cartesian product. Two relations R

Describe application programming interface, Describe Application programmin...

Describe Application programming interface? Application Programming Interface - Commercial SQL implementations take one of the two primary techniques for involving SQL in a p

Data Minnning, Can i get help with weka software

Can i get help with weka software

What is relational algebra, What is Relational Algebra? Relational algebr...

What is Relational Algebra? Relational algebra is a Procedural query Language?

What do you understand by raid, What do you understand by RAID? Explain RA...

What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re

What is authorization graph, What is authorization graph? Passing of au...

What is authorization graph? Passing of authorization from single user to another can be shown by an authorization graph.

Explain network model in dbms, Explain Network Model in DBMS? Network ...

Explain Network Model in DBMS? Network Model - It was formalised within the late year of 1960s through the Database Task Group of the Conference on Data System Language (DBTG

Functional Dependencies, What exactly is the concept of Functional Dependen...

What exactly is the concept of Functional Dependencies? And how do we associate this concept with the logic of Super-keys, Candidate Keys, etc? Given Relation R(A,B,C,D,E) with de

Case tools, explain at least five widly used case tools

explain at least five widly used case tools

Describe interfaces for the dba, Describe Interfaces for the DBA? Inte...

Describe Interfaces for the DBA? Interfaces for the DBA - Most database systems holds privileged commands which could be used only through the DBA's staff. These involves com

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