Consider relational schema and construct algebra query, Database Management System

Assignment Help:

Consider the following relational schema:
PERSON (SS#, NAME, ADDRESS)
CAR (REGISTRATION_NUMBER, YEAR, MODEL)
ACCIDENT (DATE, DRIVER, CAR_REG_NO)
OWNS (SS#, LICENSE)

Construct the subsequent relational algebra queries:
(i) Find out the names of persons who are included in an accident.
(ii) Find out the registration number of cars that were not involved in any accident.
Ans: (i) πNAME(PERSON) ∩ πDRIVER(ACCIDENT)
(ii) πREGISTRATION_NUMBER(CAR) - πCAR_REG_NO(ACCIDENT)


Related Discussions:- Consider relational schema and construct algebra query

Find out employee who draws salary more than average , Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE

Explain the natural join, Explain the Natural join Natural join is a bi...

Explain the Natural join Natural join is a binary operator which is written as (R* S) in which R and S are relations. The effect of the natural join is the set of all combinati

Query to delete constraint from alter table, A constraint named less_than_2...

A constraint named less_than_20 was defined on the field date_of_birth of table student. Delete this constraint. ALTER TABLE student DROP CONSTRAINT less_than_20;

Related fields in a database are grouped in which form, Related fields in a...

Related fields in a database are grouped in which form? Related data fields in a database are grouped to form a data record. (A record is a collection of related fields)

Need for distributed database systems, Need For Distributed Database System...

Need For Distributed Database Systems A distributed database is a set of database kept on multiple computers that appears to applications as a one database. As a result, an app

Define the canonical cover, Define the Canonical cover Ans: A canonical...

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 dependen

Create a database, The database will enable college administrators the abil...

The database will enable college administrators the ability to track students initial major. This will help college officials decide how best to prepare students for their goals an

Illustrate the term- abstracting out common behaviour, Illustrate the term-...

Illustrate the term- Abstracting Out Common Behaviour Inheritance is not every time recognised during analysis phase of development, thus it is necessary to re-evaluate object

Write short notes on domain relational calculus, Write short notes on domai...

Write short notes on domain relational calculus   The domain relational calculus uses domain variables that take on values from an attribute domain rather than values for whole

Discuss the term- design optimization, Discuss the term- Design Optimizatio...

Discuss the term- Design Optimization  We have seen various ways of representing the objects.The fundamental design model uses analysis model as the framework for implementati

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