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 traditional programming languages, How persistent programming langu...

How persistent programming languages differ from traditional programming languages? Database languages vary from traditional programming languages in that they directly manipul

Illustrate the definition of the classes and operation, The definition of t...

The definition of the classes and operation can often be adjusted to increase the amount of inheritance". Justify the above statement.   Adjustment of Inheritance The def

What is waterfall model, Waterfall model is the linear model. The process i...

Waterfall model is the linear model. The process is completed by step by step. We couldn't stop in between of the process. Prototype model: after get the model by low cost budget o

What is a query tree, What is a query tree?     Ans:  A query tree, as ...

What is a query tree?     Ans:  A query tree, as well known as operator graph, is a tree data structure that corresponds to a relational algebra expression. It denotes the inpu

Define raid structure, Define raid? Briefly explain it? A range of disk...

Define raid? Briefly explain it? A range of disk organization methods, collectively called redundant arrays of independent disks (RAID) o   Improvement of reliability throug

Determine the strong and weak entity, Determine the Strong and Weak Entity ...

Determine the Strong and Weak Entity Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and a

Create an entity relationship diagram, Cyber Transit Ltd keeps up-to-date i...

Cyber Transit Ltd keeps up-to-date information on the processing and current position of each dispatched item. Dispatched items are the main concern of the Cyber Transit product tr

Deletion anomalies-data redundancy, Deletion Anomalies: Loss of important ...

Deletion Anomalies: Loss of important Information: In some cases, useful information may be lost when a tuple is deleted. For instance, if we delete the tuple corresponding to stu

Relational database management, For this application, we will consider IBM ...

For this application, we will consider IBM DB2 catalog data (i.e., metadata) for IBM's enterprise-class servers running the z/OS (formerly OS/390 or MVS) operating system.  One of

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