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

I need automated trading engine for crypto currencies, Project Description:...

Project Description: Looking to prepare automated trading engine for alternate cyprto currencies starting with Cryptsy, finally integrating into other exchanges. Need to work wi

What is conceptual schema, What is conceptual schema? The schemas at th...

What is conceptual schema? The schemas at the view level are known as subschema that describe dissimilar views of the database.

Explain the systems development life cycle, Explain the systems development...

Explain the systems development life cycle. This is the traditional method to develop, maintain, and replace information systems that contains the project identification and se

Data manipulation language, Question 1 Discuss about second normal form an...

Question 1 Discuss about second normal form and third normal form Question 2 Write short note on                        1) Data Manipulation Language 2) Data Definition La

Dbms, statical data

statical data

Relationship sets, A relationship set is a set of relationships of the simi...

A relationship set is a set of relationships of the similar type. For example, let consider the relationship among two entities sets course and student. Collection of all the in

Design and building a distributed information system, prototype of a distri...

prototype of a distributed information system for a national car part retail outlet chain.

Define cardinality and participation constraints, Define cardinality and pa...

Define cardinality and participation constraints on a relationship type, completeness constraint on generalization.        Ans: Cardinality defines the number of entities to wh

Describe the storage structure of indexed sequential file, Describe the sto...

Describe the storage structure of indexed sequential files and their access method. Ans: Index offers a lookup capability to rapidly reach the vicinity of the desired record.

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