Define transitive dependencies, Database Management System

Assignment Help:

What do you understand by transitive dependencies? Define with an example any two problems that can take place in the database if transitive dependencies are available in the database.

 Ans:  Assume X, Y, and Z are the set of attributes. If X → Y and Y → Z afterwards the functional dependency X → Z is a transitive functional dependency. Alternatively, if a nonkey attribute is as well functionally dependent on the other nonkey attribute(s), then there is a transitive functional dependency. Transitive functional dependencies are as well cause the data redundancies and the other consequences. For instance, consider the subsequent relation:

CREATE TABLE CONTACTS

(CONTACT_ID NUMBER (5) PRIMARY KEY,

 L_NAME   VARCHAR (20),

 F_NAME   VARCHAR (20),

 COMPANY_NAME VARCHAR (20),

 COMPANY_LOCATION VARCHAR (50))

 In the following relation, all the nonkey attributes are functionally dependent on the primary key, that is CONTACT_ID. But, there is as well a transitive functional dependency exists in the relation - CONTACT_ID  COMPANY_LOCATION because CONTACT_ID → COMPANY_NAME and COMPANY_NAME →COMPANY_LOCATION.  The result of transitive dependency, there are anomalies in the above relation like this:

  • Insertion Anomaly - A new company cannot be inserted till a contact person has been assigned to that company.
  • Deletion Anomaly - If a company has just only one contact person and is deleted from the table, we will lose the information about that company, as the company information is related with that person.
  • Update Anomaly - If a company changes its location we will should make the changes in all the records in which the company name appears.

Related Discussions:- Define transitive dependencies

What is a built-in, What is a Built-in A notation of identity is built-...

What is a Built-in A notation of identity is built-into the data model or programming language and no user-supplied identifier is needed. This form of identity is used in objec

Explain relational model and their use in dbms, Explain Relational model an...

Explain Relational model and their use in DBMS? Relational Model - The relational model was first introduced through E.F. Codd of the IBM Research in the year of 1970. The mode

Define normalization, Normalization :It is a process of examine the given ...

Normalization :It is a process of examine the given relation schemas based on their primary key and Functional Dependencies (FDs) to achieve the properties Minimizing redun

aggregate functions-data manipulation language, Aggregate functions ...

Aggregate functions Some of these functions are min, count, max, and avg. These functions help in getting consolidated information from a set of tuples. Example:

What is abstraction, What is abstraction? Abstraction in the object ori...

What is abstraction? Abstraction in the object orientation is a idea that provide opportunity to express necessary properties of object without providing much details of the im

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

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

Query, Use a Set operator to create a list of academics who have written or...

Use a Set operator to create a list of academics who have written or co-written less than 5 papers and also have greater than 3 interests. List their academic number in the output.

How to control as concurrent tasks, Control as Concurrent Tasks The ex...

Control as Concurrent Tasks The expression control as simultaneous task means applying control for those events of object which can happen simultaneously. An object can be imp

Compare the two log based recovery schemes, Compare the two log-based recov...

Compare the two log-based recovery schemes in terms of ease of implementation and overhead cost.    Ans:  There are two types of log based recovery techniques: deferred update

Explain the acid properties of a transaction, Explain the ACID properties o...

Explain the ACID properties of a transaction Ans: ACID properties are a significant concept for databases. The ACID stands for Atomicity, Consistency, Isolation, and Durability

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