List the armstrong axioms for functional dependencies, Database Management System

Assignment Help:

List the Armstrong's axioms for functional dependencies.  What do you understand by soundness and completeness of these axioms?    

 Ans: The Armstrong's axioms are:

  • F1: Relexivity: If X is a set of attributes and Y ⊆ X afterwards X →Y holds.
  • F2: Augmentation: If X → Y holds and Z is a set of attributes afterwards XZ →YZ.
  • F3: Transitivity: {X → Y, Y → Z} |= {X→Z}

 

Soundness: By sound, we mean that a specified set of functional dependencies F specified on a relation schema R, any dependency which we can infer from F by using F1 by F3 holds in each relation state r of R that satisfies the dependencies in F.

Completeness: By complete, we mean that by using F1 through F3 frequently to infer dependencies until no more dependencies can be inferred results in the whole set of all possible dependencies which can be inferred from F.


Related Discussions:- List the armstrong axioms for functional dependencies

Assignment, how does Btree differ from a B+ - tree?

how does Btree differ from a B+ - tree?

Mobile database, write short note on mobile database

write short note on mobile database

Define query language, Define query language?   A query is a statement ...

Define query language?   A query is a statement requesting the retrieval of information. The portion of DML that includes information retrieval is known as a query language.

What is called an evaluation primitive, What is called an evaluation primit...

What is called an evaluation primitive? A relational algebra operation annotated with instructions on how to evaluate is known as an evaluation primitive.

Data, Explain three main attributes of data.

Explain three main attributes of data.

Creating database for library, i need help with creating database system fo...

i need help with creating database system for a library

Division operation, To do the division operation R1 ÷ R2, R2 should be a co...

To do the division operation R1 ÷ R2, R2 should be a correct subset of R1. In the following example R1 have attributes A and B and R2 have only attribute B so R2 is a correct subse

Create records in a table - data structures, In this exercise you will crea...

In this exercise you will create ten records, each containing the following fields: student name, class:  Freshman, Sophomore, Junior or Senior, Major:  Liberal Arts or General Sci

Evaluate the null hypothesis, 1.Suppose you are given a dataset that consis...

1.Suppose you are given a dataset that consists of a random sample of tasters, on which the following variables were obtained: (y) Zpref = taste preference for green beans store

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