What is functional dependency, Database Management System

Assignment Help:

What is Functional Dependency?

A Functional dependency is shown by X Y among two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they have t1[Y] = t2[Y]. This means the value of X component of a tuple uniquely verifies the value of component Y.

 


Related Discussions:- What is functional dependency

Describe data manipulation language, Describe Data Manipulation language ? ...

Describe Data Manipulation language ? Data Manipulation Language (DML) - A data manipulation language is a language which enables users to access or manipulate data as organize

Inconsistent analysis-problems of concurrent transactions, Inconsistent Ana...

Inconsistent Analysis : The problem as given with transactions T1 and T2 where two transactions interleave to make incorrect result during an analysis by Audit is the instance of s

Managing database, 10A.53 Code an Oracle Database trigger to enforce the ...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

Define the terms - physical schema and logical schema, Define the terms  1)...

Define the terms  1) physical schema 2) logical schema.  Physical schema:  The physical schema explains the database design at the physical level, which  is  the  lowest  lev

In which relational modes cardinality is termed, In which relational modes,...

In which relational modes, cardinality is termed? Answer : Cardinality is termed in a number of tuples relational modes.

Create table, What are the advantages of creating a table from existing tab...

What are the advantages of creating a table from existing table?

Two phase locking (2pl), Two Phase Locking (2PL) The two-phase locking ...

Two Phase Locking (2PL) The two-phase locking protocol having of two phases: Phase 1 : The lock acquisition phase : If a transaction T needs to read an object, it wants to

ERD, online eductional management system ke diagram

online eductional management system ke diagram

Describe the major steps in the implementation process, Question: (a) ...

Question: (a) One of the steps in the five-step problem-solving model is implementation. Implementation is considered a key step in the problem-solving model. A problem may be

Explain tuple variable, Define tuple variable? Tuple variables are used...

Define tuple variable? Tuple variables are used for comparing two tuples in the same relation. The tuple variables are explained in the from clause by way of the as clause.

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