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

How to create a table from existing table, How to create a table from exist...

How to create a table from existing table? Create table as e.g, To create a new table ‘N_emp' with employee names and their identification numbers only from employee ta

Design and building a distributed information system, prototype of a distri...

prototype of a distributed information system for a national car part retail outlet chain.

Discuss the three level architecture of dbms, PRINCIPLES OF DATABASE 1....

PRINCIPLES OF DATABASE 1. State the following terms: a) Database b) Database Management System c) Entity d) Attribute e) Relationship 2. Discuss the Three Level Architecture

When are they useful justify with an example, When are they useful? Justify...

When are they useful? Justify with an example. The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent t

Difference between internal tables and extra datasets, What is the differen...

What is the difference between internal tables and extract datasets? The lines of an internal table always have the similar structure. By using extract datasets, you can ha

Why object-oriented system use the relational dbms, Why, generally does an ...

Why, generally does an object-oriented system use the relational DBMS? The reasons for using relational DBMS for OO systems could be any combination of following: a. Many or

Define average seek time, Define average seek time. The average seek ti...

Define average seek time. The average seek time is the average of the seek times, calculated over a sequence of random requests.

Example of transaction? , Example :; transfers transfer_amount from x's acc...

Example :; transfers transfer_amount from x's account to y's account ; Supposes x&y both accounts exist TRANSACTION (x, y, transfer_amount) Start transaction IF X AND Y

Explain current page table and shadow page table, Explain current page tabl...

Explain current page table and shadow page table. The key idea behind the shadow paging method is to maintain two page tables during the life of the transaction: the current pa

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