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

Glory be, what does glory be mean

what does glory be mean

In which form of relational database developer refers, In which form of rel...

In which form of relational database developer refers to a record? In a tuple form of relational database developer refers to a record.

Describe participation constraints, Describe Participation Constraints? ...

Describe Participation Constraints? Participation Constraints - The participation constraint exacts whether the existence of an entity depends on its being related to another

What are deadlocks, What are deadlocks?  How can they be avoided?  Ans:...

What are deadlocks?  How can they be avoided?  Ans: Deadlock considers to a particular condition when two or more processes are every waiting for another to release a resource,

Data control, Identify the need and use of data control through problem sol...

Identify the need and use of data control through problem solving, illustration

Give detail explanation about cross-section of twisted pair, The cross-sect...

The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per

Memory components of sga, Problem 1. Describe the Oracle Architecture w...

Problem 1. Describe the Oracle Architecture with a neat labeled diagram, Also explain the individual components of the Architecture. 2. Write about the following Oracle 9i o

Special workarea for interface, While using extract datasets it is required...

While using extract datasets it is required to have a special workarea for interface False.  It is not required to have a special workarea for interface

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