Define the canonical cover, Database Management System

Assignment Help:

Define the Canonical cover

Ans: A canonical cover F_c for F is a set of dependencies like F logically implies all dependencies in F_c, and F_c logically entails all dependencies in F. F_c must have the subsequent properties:

No functional dependency in F_c consists of extraneous attribute
Every left side of a functional dependency in F_c is unique. Which is, there are no two dependencies α₁→ β₁ and α₂→β₂ in F_c such that α₁ = α₂.

F_c is minimal in certain sense - it does not consist of extraneous attributes, and it combines functional dependencies with similar left side. It is cheaper to test F_c than it is to test F itself.

Related Discussions:- Define the canonical cover

Determine that the checkpoints are a part of, 1. Determine that the Checkpo...

1. Determine that the Checkpoints are a part of Ans: Checkpoints are a part of Recovery measures

Lack of standards and experience, Lack of standards and experience: The la...

Lack of standards and experience: The lack of standards has considerably limited the potential of distributed DBMSs. As well, there are no tools or methodologies to help users cha

Why as clause is used in sql, Why 'AS' clause is used in SQL ? 'As' cla...

Why 'AS' clause is used in SQL ? 'As' clause is used for Rename operation. ‘AS' clause is used in SQL for rename operation. (e.g., SELECT ENO AS EMPLOYEE_NO FROM EMP)

Keys - relational database integrity, Candidate Key: In a relation R, a ca...

Candidate Key: In a relation R, a candidate key for R is a subset of the set of attributes of R, which have the differnt two properties: (1) Uniqueness: N

ER diagram, sir we want er diagram of bank management system in this main m...

sir we want er diagram of bank management system in this main menu option as new account,deposit amount,withdraw amount,all acount holder list,modify account,close account

How does the two phase protocol ensure serializability, How does the two ph...

How does the two phase protocol ensure serializability in database schedules? Ans: A transaction is termed to follow the two-phase locking protocol if all locking operations

E-r diagram, Let us now make the E-R diagram for the student database as pe...

Let us now make the E-R diagram for the student database as per the explanation given in the previous section. We can also states the overall logical structure of a database usi

Which two files are used during operation of the dbms, Which two files are ...

Which two files are used during operation of the DBMS? Data dictionary and transaction log are two files used during operation of the DBMS.

Benefits and drawbacks of heap files, Benefits of heap files 1. This i...

Benefits of heap files 1. This is a easy file Organisation method. 2. Insertion is somehow capable. 3. Good for bulk-loading data into a table. 4. Best if file

Explain in details about data sharing, Explain in details about Data Shari...

Explain in details about Data Sharing

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages