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

Explain er relationship model, Explain ER Relationship model? An entity...

Explain ER Relationship model? An entity-relationship model (ERM): An entity-relationship model (ERM) is an abstract theoretical illustration of structured data. Entity-relatio

Data warehousing and business intelligence, I need help with data warehousi...

I need help with data warehousing and business intelligence course project about designing a data warehouse for a jewelry company that does not have one

What are the ways in which signal can be generated, What are the ways in wh...

What are the ways in which signal can be generated A signal might be generated in many ways such as a Signal is result of particular physical condition. Whenever a process writ

What is a homogeneous distributed database, What is a homogeneous distribut...

What is a homogeneous distributed database? In homogeneous distributed databases, all sites have the same database management system software, are aware of one another, and agr

Advantages to copying records from one table to another, What kind of advan...

What kind of advantages to copying records from one table to another? -) When an algorithm that modifies a table is used after that it's safer to work with the copy -) When

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

Design and prototype, This assignment is worth 45% of your final grade for ...

This assignment is worth 45% of your final grade for this module.  Marks will be awarded as follows: Prototypes (wireframe and web based prototype) You are expected

Databases and data warehouses , Databases and data warehouses both are data...

Databases and data warehouses both are databases and both contains number of rows and columns of tables containing data. Data warehouse is really different from databases because d

Whst is logical schema, Whst is logical schema ? Logical schema is the ...

Whst is logical schema ? Logical schema is the entire database.

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