CoderFunda
  • Home
  • About us
    • Contact Us
    • Disclaimer
    • Privacy Policy
    • About us
  • Home
  • Php
  • HTML
  • CSS
  • JavaScript
    • JavaScript
    • Jquery
    • JqueryUI
    • Stock
  • SQL
  • Vue.Js
  • Python
  • Wordpress
  • C++
    • C++
    • C
  • Laravel
    • Laravel
      • Overview
      • Namespaces
      • Middleware
      • Routing
      • Configuration
      • Application Structure
      • Installation
    • Overview
  • DBMS
    • DBMS
      • PL/SQL
      • SQLite
      • MongoDB
      • Cassandra
      • MySQL
      • Oracle
      • CouchDB
      • Neo4j
      • DB2
      • Quiz
    • Overview
  • Entertainment
    • TV Series Update
    • Movie Review
    • Movie Review
  • More
    • Vue. Js
    • Php Question
    • Php Interview Question
    • Laravel Interview Question
    • SQL Interview Question
    • IAS Interview Question
    • PCS Interview Question
    • Technology
    • Other

08 April, 2022

Inference Rule

 Programing Coderfunda     April 08, 2022     DBMS     No comments   

 

Inference Rule (IR):

  • The Armstrong's axioms are the basic inference rule.
  • Armstrong's axioms are used to conclude functional dependencies on a relational database.
  • The inference rule is a type of assertion. It can apply to a set of FD(functional dependency) to derive other FD.
  • Using the inference rule, we can derive additional functional dependency from the initial set.

The Functional dependency has 6 types of inference rule:

1. Reflexive Rule (IR1)

In the reflexive rule, if Y is a subset of X, then X determines Y.

  1. If X ⊇ Y then X  →    Y  

Example:

  1. X = {a, b, c, d, e}  
  2. Y = {a, b, c}  

2. Augmentation Rule (IR2)

The augmentation is also called as a partial dependency. In augmentation, if X determines Y, then XZ determines YZ for any Z.

  1. If X    →  Y then XZ   →   YZ   

Example:

  1. For R(ABCD),  if A   →   B then AC  →   BC  

3. Transitive Rule (IR3)

In the transitive rule, if X determines Y and Y determine Z, then X must also determine Z.

  1. If X   →   Y and Y  →  Z then X  →   Z    

4. Union Rule (IR4)

Union rule says, if X determines Y and X determines Z, then X must also determine Y and Z.

  1. If X    →  Y and X   →  Z then X  →    YZ     

Proof:

1. X → Y (given)
2. X → Z (given)
3. X → XY (using IR2 on 1 by augmentation with X. Where XX = X)
4. XY → YZ (using IR2 on 2 by augmentation with Y)
5. X → YZ (using IR3 on 3 and 4)

5. Decomposition Rule (IR5)

Decomposition rule is also known as project rule. It is the reverse of union rule.

This Rule says, if X determines Y and Z, then X determines Y and X determines Z separately.

  1. If X   →   YZ then X   →   Y and X  →    Z   

Proof:

1. X → YZ (given)
2. YZ → Y (using IR1 Rule)
3. X → Y (using IR3 on 1 and 2)

6. Pseudo transitive Rule (IR6)

In Pseudo transitive Rule, if X determines Y and YZ determines W, then XZ determines W.

  1. If X   →   Y and YZ   →   W then XZ   →   W   

Proof:

1. X → Y (given)
2. WY → Z (given)
3. WX → WY (using IR2 on 1 by augmenting with W)
4. WX → Z (using IR3 on 3 and 2)

  • Share This:  
  •  Facebook
  •  Twitter
  •  Google+
  •  Stumble
  •  Digg
Email ThisBlogThis!Share to XShare to Facebook
Newer Post Older Post Home

0 comments:

Post a Comment

Thanks

Meta

Popular Posts

  • Sitaare Zameen Par Full Movie Review
     Here’s a  complete Vue.js tutorial for beginners to master level , structured in a progressive and simple way. It covers all essential topi...
  • AI foot tracking model
    I am a student doing a graduation project. I urgently need to deal with this model (I am attaching a link). I've never worked with pytho...
  • Laravel Search String
      Laravel Search String is a package by   Loris Leiva   that generates database queries based on one unique string using a simple and custom...
  • Writing and debugging Eloquent queries with Tinkerwell
    In this article, let's look into the options that you can use with Tinkerwell to write and debug Eloquent queries easier. The post Wr...
  • Laravel - Installation
    For managing dependencies, Laravel uses   composer . Make sure you have a Composer installed on your system before you install Laravel. In t...

Categories

  • Ajax (26)
  • Bootstrap (30)
  • DBMS (42)
  • HTML (12)
  • HTML5 (45)
  • JavaScript (10)
  • Jquery (34)
  • Jquery UI (2)
  • JqueryUI (32)
  • Laravel (1017)
  • Laravel Tutorials (23)
  • Laravel-Question (6)
  • Magento (9)
  • Magento 2 (95)
  • MariaDB (1)
  • MySql Tutorial (2)
  • PHP-Interview-Questions (3)
  • Php Question (13)
  • Python (36)
  • RDBMS (13)
  • SQL Tutorial (79)
  • Vue.js Tutorial (69)
  • Wordpress (150)
  • Wordpress Theme (3)
  • codeigniter (108)
  • oops (4)
  • php (853)

Social Media Links

  • Follow on Twitter
  • Like on Facebook
  • Subscribe on Youtube
  • Follow on Instagram

Pages

  • Home
  • Contact Us
  • Privacy Policy
  • About us

Blog Archive

  • July (4)
  • September (100)
  • August (50)
  • July (56)
  • June (46)
  • May (59)
  • April (50)
  • March (60)
  • February (42)
  • January (53)
  • December (58)
  • November (61)
  • October (39)
  • September (36)
  • August (36)
  • July (34)
  • June (34)
  • May (36)
  • April (29)
  • March (82)
  • February (1)
  • January (8)
  • December (14)
  • November (41)
  • October (13)
  • September (5)
  • August (48)
  • July (9)
  • June (6)
  • May (119)
  • April (259)
  • March (122)
  • February (368)
  • January (33)
  • October (2)
  • July (11)
  • June (29)
  • May (25)
  • April (168)
  • March (93)
  • February (60)
  • January (28)
  • December (195)
  • November (24)
  • October (40)
  • September (55)
  • August (6)
  • July (48)
  • May (2)
  • January (2)
  • July (6)
  • June (6)
  • February (17)
  • January (69)
  • December (122)
  • November (56)
  • October (92)
  • September (76)
  • August (6)

Loading...

Laravel News

Loading...

Copyright © CoderFunda | Powered by Blogger
Design by Coderfunda | Blogger Theme by Coderfunda | Distributed By Coderfunda