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

.DBMS, please describe the data base management with the easy example &giv...

please describe the data base management with the easy example &give the application?

In e-r diagram how generalization is represented, In E-R diagram how genera...

In E-R diagram how generalization is represented? in E-R diagram generalization is represented by Triangle shape.

Enterprise applications integration, The figure below depicts the conceptu...

The figure below depicts the conceptual diagram of a banking system. (a) Describe one example relevant to the system in figure, for each of the 4 types of enterprise appl

Er diagrams, in an organization several projects are undertaken. Each proje...

in an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the

Nested query, what is correlation in nested query

what is correlation in nested query

What is the use of group by clause, What is the use of group by clause?  ...

What is the use of group by clause?  Group  by  clause  is  used to apply  aggregate  functions  to a  set  of  tuples. The attributes given in the group by clause are used to

Describe the algorithm to draw the dependency graph, Describe the algorithm...

Describe the algorithm to draw the dependency graph?   Ans: Algorithm to draw Precedence Graph is like this: a.  For every transaction T i participating in schedule S, make

Icloud based storage, Advantages and disadvantages of icloud based storage

Advantages and disadvantages of icloud based storage

Data, Explain three main attributes of data.

Explain three main attributes of data.

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