Write the queries in relational algebra, Database Management System

Assignment Help:

Problem:

You are given the following schema

1. Flights(flno, from, to, distance)
2. Aircraft(aid, flno, aname, cruisingRange)
3. Certified(eid, aid)
4. Employees(eid, ename, salary)

‘CruisingRange' is the distance that can be covered by an aircraft in a non-stop mode.

(i) Write the following queries in Relational Algebra.

(a) Find the names of pilots certified for 'Boeing 747' aircraft.

(b) Find the ids of all aircraft that can be used on non-stop flights from New York to Los Angeles.

(c) Find the names of pilots who can operate planes with a range greater than 3000 miles, but are not certified on 'Boeing 747' aircraft.

(ii) Write the following queries in SQL.

(a) Find the ids of employees who are not certified at all.

(b) Find the ids of all aircraft that can be used on non-stop flights from New York to Los Angeles.

Related Discussions:- Write the queries in relational algebra

Consistency error-database errors, Consistency error : These errors happen ...

Consistency error : These errors happen due to the inconsistent state of database caused may be due to wrong implementation of commands or in case of a transaction abort. To overc

Atomicity-transaction , Atomicity: It describes a transaction to be a one ...

Atomicity: It describes a transaction to be a one unit of processing. We can also say either a transaction will be finished completely or not at all. In the transaction example 1

Deadlock prevention, Deadlock Prevention One of the easiest approaches ...

Deadlock Prevention One of the easiest approaches for avoiding a deadlock would be to obtain all the locks at the begin of the transaction. Though, this approach restricts conc

Main difference between read-only and update methods, What is the main diff...

What is the main difference between read-only and update methods? A read-only method does not affect the values of a variable in an object, whereas an update method may alter t

What is dag, What is DAG? The class-subclass relationship is shown by a...

What is DAG? The class-subclass relationship is shown by a directed acyclic graph.eg: employees can be temporary or permanent. We might be create subclasses temporary \and perm

Advantages of database systems, Problem 1. Describe the following a)...

Problem 1. Describe the following a) Advantages of Database Systems b) Functions of a DBMS Explanation of part (a) and (b) 2. Explain the following concepts w

Extend the database, Now that she understands more about the benefits of da...

Now that she understands more about the benefits of databases, the play-scheme manager would like to extend the play-scheme database to include data for schools and instructors as

In a hierarchical model of data records are organized, In a Hierarchical mo...

In a Hierarchical model of data records are organized ? In the hierarchical model of data records are organized as Tree structure.

What does data dictionary is a special file contains, What does data dictio...

What does data dictionary is a special file contains ? The data dictionary is a special file contain The name of all fields in all files.The width of all fields in all files an

Define the terms entity set and relationship set, Define the terms i) Entit...

Define the terms i) Entity set ii) Relationship set Entity set: The set of all entities of the similar type is termed as an entity set. Relationship set: The set of all rela

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages