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

Working and processing files, 1.  Define each of the following IN YOUR OWN ...

1.  Define each of the following IN YOUR OWN WORDS: (a)   File: (b)   Record: (c)   Field: (d)   Primary Key: (e)   Secondary Key: 2.  A travel agency wants t

Architectural standard, Architectural standard: Designation : Archit...

Architectural standard: Designation : Architect , Consultant Job Profile : As a part of Oracle Fusion Middleware at Satyam, I am involved with Presales, Delivery, A

Objectives-database recovery and security, Objectives Define the te...

Objectives Define the terms RECOVERY and INTEGRITY; Define Recovery Techniques; Explain Error and Error detection techniques, and Define types of Authorisation.

Database management issues, You are required to write a report which evalua...

You are required to write a report which evaluates two of the following issues in relation to your case study database: a. Security issues b. Performance issues c. Backup

List the string operations supported by sql, List the string operations sup...

List the string operations supported by SQL? 1) Pattern matching Operation 2) Concatenation 3) Extracting character strings 4) Converting among uppercase and lower cas

What are the comparison operator in sql, What are the comparison operator i...

What are the comparison operator in SQL?  Comparison operator in SQL are =, LIKE and BETWEEN

Design a database table, A database named yourusernameFMA has been set up f...

A database named yourusernameFMA has been set up for you to use for this assignment.  For the FMA you must create the required tables and run the queries using this database.  If y

Illustrate the view of software architecture, Illustrate the view of softwa...

Illustrate the view of software architecture A model is a semantically closed abstraction of system composes of elements. It can be visualized using any of the following five v

Which is a legal expression in sql, Which is a legal expression in SQL? ...

Which is a legal expression in SQL? SELECT NAME FROM EMPLOYEE is a legal expression in SQL.

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