What is meant by functional dependencies, Database Management System

Assignment Help:

What is meant by functional dependencies?

Consider a relation schema R and α C R and β C R. The functional dependency α ->β  holds on relational schema R if in any legal relation r(R), for all pairs of tuples t1 and t2 in r like t1 [α] =t2 [α], and also t1 [β] =t2 [β].

 


Related Discussions:- What is meant by functional dependencies

Super keys, A super key is an attribute or set of attributes used to recogn...

A super key is an attribute or set of attributes used to recognize the records uniquely in a relation. For instance, in the Relation PERSON defines earlier PERSON_ID is a super

Enforce referential integrity, Use Access 2007 to create a database calle...

Use Access 2007 to create a database called UniLib.mdb. - this file should be created on your personal drive at the university (or C: if you're using Access 2007 at home) and t

4, explain the level architectures of the database management system

explain the level architectures of the database management system

Explain hashing techniques, Explain Hashing techniques The hashing tech...

Explain Hashing techniques The hashing techniques can be categorized as: Static Hashing Techniques - In this method, the data can be viewed a collection of buckets, along with

What is average response time, What is average response time? The avera...

What is average response time? The average response time is that the average time for a transaction to be done after it has been submitted.

What is the function of io/m signal in the 8085, What is the function of IO...

What is the function of IO/M signal in the 8085? It is a status signal. It is used to differentiate among memory locations and I/O operations. When this signal is low (IO/M = 0

Define multivalued dependency and 4nf, Define multivalued dependency and 4N...

Define multivalued dependency and 4NF.  Ans:  Multivalued Dependency - Assume R be a relation schema and let α ⊆ R and β ⊆ R. The multivalued dependency  α →→β   holds o

A distributed transaction, A Distributed Transaction Let us demonstrate...

A Distributed Transaction Let us demonstrate the concept of a distributed transaction by considering a banking system having of three branches located in 3 different cities. Ev

Differentiate between primary and secondary storage, Differentiate between ...

Differentiate between Primary and secondary storage? Primary and secondary storage - Primary storage device stores the data temporarily. Primary storage is commonly used thro

Relation and relational schema, A relation has: Relational Schema ...

A relation has: Relational Schema Relation instance Relational Schema: A relational schema shows the relation's name, its attributes and the domain of every a

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