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

What are the types of indices, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What are called journaling file systems, What are called journaling file sy...

What are called journaling file systems? File systems that support log disks are known as journaling file systems.

Explain what is to be done during defining problem statement, Briefly expla...

Briefly explain what is to be done during defining problem statement. To define Problem Statement of a system, define what is to be done and how you can go to implement that. Y

Define query by example, Define Query by Example QBE is a query languag...

Define Query by Example QBE is a query language relies upon domain calculus and has two dimensional syntax. The queries are written in the horizontal and vertical dimensions of

E r diagram, how to make an e r diagram?

how to make an e r diagram?

What are the various forms of data transparency, What are the various forms...

What are the various forms of data transparency? a) fragmentation transparency b) replication transparency c) location transparency

Describe the definition of a transaction in sql, Describe the definition of...

Describe the definition of a transaction in SQL  Ans: The SQL transaction starts implicitly. Transactions are finished by either Commit work that commits the transaction and st

Explain cnt in the respects of qbe, Explain CNT in the respects of QBE ? ...

Explain CNT in the respects of QBE ? CNT: It is one of the aggregation commands given in QBE. It is used to identify number of tuples

State about the advance object design, ADVANCE OBJECT DESIGN Introduct...

ADVANCE OBJECT DESIGN Introduction Analysis is the initial step of the OMT methodology. It is apprehensive with devising a precise, concise, correct and understandable mo

Define boyce codd normal form, Define Boyce codd normal form A relation...

Define Boyce codd normal form A relation schema R is in BCNF with respect to a set F of functional dependencies if, for all functional dependencies in F + of the form.α ->β.

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