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

State in brief about object design, Give the Introduction of OBJECT DESIGN ...

Give the Introduction of OBJECT DESIGN Strategies which are selected during system design are carried out in object-oriented design. In this procedure, objects which are identi

xml, basic structure of xm

basic structure of xml

What three major types of actions includes databases, What three major type...

What three major types of actions includes databases? Briefly discuss these The three major types of actions including databases are: (i) Defining: It includes specifyin

Describe the advantage of state chart diagram, Describe the advantage of St...

Describe the advantage of State chart Diagram A state chart represents a state machine, emphasizing flow of control from one state to other. A state machine is a behaviour whi

Tables, does tables are called relations

does tables are called relations

What is specialization, What is Specialization? Specialization: Special...

What is Specialization? Specialization: Specialization permits you to describe new types of information (new structural types or latest domains of information), although reusin

Linear commit protocol, With the linear commit protocol, sites are connecte...

With the linear commit protocol, sites are connected in a chain, and the subtransaction at the left-hand end of the chain initiates the protocol. Propose a crash recovery protocol

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