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

Assignments, i have assignments I don''t have time to finish because of wo...

i have assignments I don''t have time to finish because of work and other assignments, can you help with this? All are from the book Darabase design, application development and a

Explain about database system structure, Explain about database system stru...

Explain about database system structure? Storage manager Authorization and integrity manager Transaction manager File manager Buffer manager Storage manager

What is object identity, What is object identity? An object retains its...

What is object identity? An object retains its identity even if some or all the values of variables or explanations of methods change overtime.

How the time stamps are implemented, How the time stamps are implemented ...

How the time stamps are implemented Use the value of the system clock as the time stamp. That is a transaction's time stamp is equivalent to the value of the clock when the tra

Explain how the binary tree, QUESTION (a) Give two advantages of using ...

QUESTION (a) Give two advantages of using Linked List as compared to arrays. (b) (i) You are working as programmer at the Orange Mauritius branch. You have been asked to cre

How can you map null values to other values while display, How can you map ...

How can you map NULL values to other values while display? IF( ) , IFNULL( ) keywords are used to do so. They are 'LIMIT' is used for the following kinds of problems: 1) Ans

What is a disjoint less constraint, What is a disjoint less constraint? ...

What is a disjoint less constraint? Ans: It needs that an entity belongs to no much more than one level entity set.  Disjoint less constraint needs that an entity belongs to

Explain query tree represent relational algebra expression, How does a quer...

How does a query tree represent a relational algebra expression?      Ans: This includes transforming an initial expression (tree) into an equivalent expression (tree) that is

What creates while a primary key is combined with a foreign, What it create...

What it creates while a primary key is combined with a foreign key? It creates Parent-Child relation ship between the tables that connect them while a primary key is combined w

Explain what is relation, Explain What is Relation? A database relatio...

Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.

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