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

Benefits abd drawback of hashed file organisation, Benefits of Hashed file ...

Benefits of Hashed file Organisation 1. Insertion or search on hash-key is quick. 2. Best if equality search is required on hash-key. Drawbacks of Hashed file

Explain the shadow paging recovery technique, Explain the shadow paging rec...

Explain the shadow paging recovery technique. Ans: Shadow paging is a method used to acquire atomic and durable transactions, and provides the capability to manipulate pages i

What is message switching, What is Message switching Message switching ...

What is Message switching Message switching transmits data units which can be arbitrarily long. Packet switching has a utmost packet size, if any message longer than that, it s

Update opreation, notes about update opreation

notes about update opreation

What do you understand by data ware house, Question 1: Define the term ...

Question 1: Define the term business intelligence tools? Briefly explain how the data from one end gets transformed into information at the other end? Definition Exp

Express the ways provided by mysql for pattern matching, Express the ways p...

Express the ways provided by MySQL for Pattern Matching? MySQL provides two kinds of pattern matching. 1) One is based on SQL patterns 2) Regular expressions.

Describe the relational model, a) Distinguish between ‘database' and ‘Data...

a) Distinguish between ‘database' and ‘Database Management Systems (DBMS)'. b) List and briefly describe five potential benefits of the database approach compared to conventio

Job scheduling strategy, 1) Define a job scheduling strategy that will meet...

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

Domains, A domain is a set of permissible values that can be given to an at...

A domain is a set of permissible values that can be given to an attribute. So each attribute in a table has a definite domain. Values to these attributes cannot be assigned outside

Illustrate the state model for the atm class, Illustrate the State model fo...

Illustrate the State model for the ATM class let us take state model for the ATM class given below in Figure showing state model of the ATM class and the pseudo code derived fr

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages