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

Proposed information analysis, Add generation capabilities and/or tailor th...

Add generation capabilities and/or tailor the built-in functionality of generator. This enables you to produce "all" the test data for the MySQL tables you produced in the previous

Descrine an data dictionary, Describe an data dictionary? A data dictio...

Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.

Update anomaly-data redundancy, Update Anomaly : This anomaly is occurred d...

Update Anomaly : This anomaly is occurred due to data redundancy. Redundant information makes updates more complex since, for example, varying the name of the instructor of MCS-014

Explain how the binary tree, QUESTION (a) Give two advantages of using ...

QUESTION (a) Give two advantages of using Linked List as compared to arrays. (b) (i) You are working as programmer at the Orange Mauritius branch. You have been asked to cre

Define weak and strong entity sets, Define weak and strong entity sets?  ...

Define weak and strong entity sets?  Weak entity  set:  entity  set  that  do not  have  key  attribute  of  their  own are  known as weak entity sets.  Strong entity set

Data Warehousing Job Scheduling, 1) Define a job scheduling strategy that w...

1) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pict

Which database object does not physically exist, Which database object does...

Which database object does not physically exist? A view database object does not physically exist.

Database problem in wordpress, Project Description: I am having a random...

Project Description: I am having a random problem with my Wordpress site. If I click on "Publish" and "Add new", it takes me to a 404 page not found of /wp-admin/post.php (th

Misuse of data or a database, As with other software, databases can potenti...

As with other software, databases can potentially be used for unethical purposes. As a database developer, and a consumer, you should recognize database misuse, and how it may affe

Data redundancy, Data Redundancy -A lot of information is being repeated in...

Data Redundancy -A lot of information is being repeated in the relation. For instance, the information that MCS-014 is named SSAD is repetitive, address of Rahul is "D- 27, Main ro

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