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

Logical entity relationship diagrams, How can i turn a conceptual entity re...

How can i turn a conceptual entity relationship diagram into a logical entity relationship diagram? what do i have to do with "mandetory or" and "optional or" relationships?

Set concept is used in which type of modelling, SET concept is used in whic...

SET concept is used in which type of modelling? SET concept is used in Network Model.

Define database management system, Normal 0 false false fal...

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

Write a query to find name from the relational algebra, Consider the relati...

Consider the relations City (city_name, state) Hotel (name, address) City_hotel (hotel_name, city_name, owner) Answer the following queries in relational algebra (i) Find

How we can implement relationships when designing tables, You want to imple...

You want to implement following relationships when designing tables. How would you do it? a.) One-to-one b.) One-to-many c.) Many-to-many a.) One-to-One relationship -

BI, (a) Why did SAP introduce the extended star schema?

(a) Why did SAP introduce the extended star schema?

Cartisian product, Explain the cartesian product in Database Management Sys...

Explain the cartesian product in Database Management System

Design a large scale system, Question: (a) Why is it important to know...

Question: (a) Why is it important to know the architecture rather than to start requirement capture when designing a large scale system? (b) Who are the different people in

Data fragmentation in distributed database system, brief history,definition...

brief history,definition,current trends and future trends if any of data fragmentation

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