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

What is system log, What is system log?  What are the entries?       An...

What is system log?  What are the entries?       Ans:  The system log that is generally written on stable storage contains the redundant data required to recover from volatile

Finkelstein methodology, PART MARKING: For this section, we will use part m...

PART MARKING: For this section, we will use part marking. This means we will supply model answers to all questions but we will only mark six questions. We will choose these randoml

By which techniquestransaction processing is associated, By which technique...

By which techniquesTransaction processing is associated? Transaction processing is associated by producing detail, summary, or exception reports and recording a business activi

Database manager, Database Manager It is the interface among low-leve...

Database Manager It is the interface among low-level data, queries and application programs. Databases typically need a large amount of storage space. It is kept on disks, as

Explain the management of data store, Explain the Management of Data Store ...

Explain the Management of Data Store Every system irrespective of its nature of application requires storing permanent data for consequent use in problem solving. Some objects

What is the use of sub queries, What is the use of sub queries? A sub q...

What is the use of sub queries? A sub query is a select-from-where expression that is nested with in another query. A common use of sub queries is to do tests for set membershi

What are the drawbacks of shadow-paging technique, What are the drawbacks o...

What are the drawbacks of shadow-paging technique? The drawbacks of shadow paging is:- a) Commit Overhead b) Data fragmentation c)  Garbage collection

Describe database state in details, Describe Database state in details? ...

Describe Database state in details? Database state: The actual data within the database at a particular moment in time is known as a database state.

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