Give expression in tuple calculus and domain calculus, Database Management System

Assignment Help:

Consider the subsequent relation schemes:

 Project (Project#, Project_name, chief_architect)

 Employee (Emp#, Empname)

 Assigned_To (Project#, Emp#)

 Give expression in Tuple calculus and Domain calculus for each of the queries below:

 (i) Get the employee numbers of employees who work on all projects.

 (ii) Get the employee numbers of employees who do not work on the COMP123 project.

 Ans:   (i) Tuple Calculus:

 {t[Emp#] | t ∈ ASSIGNED_TO ∧ ∀p (p ∈ PROJECT ∃u (u ∈ ASSIGNED_TO ∧ p[Project#] = u[Project#] ∧ t[Emp#] = u[Emp#]))}

 Domain Calculus:

 {e | ∃p ( ∈ ASSIGNED_TO ∧ ∀p1 ( ∈ PROJECT   ∈ ASSIGNED_TO))}

(ii) Tuple Calculus:

{t[Emp#] | t ∈ ASSIGNED_TO ∧ ¬∃u (u ∈ ASSIGNED_TO  ∧ u[Project#] = 'COMP123'∧ t[Emp#] = u[Emp#])}

 Domain Calculus:

 {e | ∃p ( ∈ ASSIGNED_TO ∧ ∀p1, e1 ( ∉ ASSIGNED_TO  ∨ p1 ≠ 'COMP123' ∨ e1 ≠ e))}


Related Discussions:- Give expression in tuple calculus and domain calculus

Relational DB, Suppose R is a relation with attributes A1, A2,..., An. As a...

Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if: 1.1 The only key is A1. 1.2 The only key is A1 and A2. 1.3 The o

External failure-database recovery and security, External failure : A failu...

External failure : A failure can also result because of an external cause, such as earthquakes, fire, floods, etc. The database must be duly backed up to avoid troubles occurring d

Queries, Find the names of all Albums that have more than 30 tracks. Result...

Find the names of all Albums that have more than 30 tracks. Result: (name: varchar(255))

Er database theoretical and modeling database system, Need an expert in ER ...

Need an expert in ER database theoretical and modeling database system Project Description: Need an expert in ER database theoretical and modeling database systems? Skills

Differentiate between procedural and non procedural language, Differentiate...

Differentiate between Procedural and non procedural languages ? Procedural and non procedural languages - A procedural language specifies the operations to be performed on th

To delete a particular column in a relation which command, To delete a part...

To delete a particular column in a relation which command is used ? To delete a particular column in a relation ALTER command is used.

Key to represent relationship between tables is called, Key to represent re...

Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.

Create a database for store company details, You group has been hired by  T...

You group has been hired by  TrainingrUs.com to keeps track of training revenues. TrainingrUS.com wants you to keep scheduling. COURSE table contains following information:

Develop a simple database of student records, In this programming assignmen...

In this programming assignment, you will develop a simple database of student records. Here are the requirements: 1) A student record contains a name and a number. We assume tha

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