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

Create an entity relationship diagram, Create an entity relationship diagra...

Create an entity relationship diagram, Database Management System

What is the need for triggers, What is the need for triggers? Triggers ...

What is the need for triggers? Triggers are useful mechanisms for alerting humans or for starting particular tasks automatically when particular conditions are met.

Explain candidate key, Explain Candidate key? Candidate Key - A candi...

Explain Candidate key? Candidate Key - A candidate key is a minimal superkey, that can be used to uniquely identify a tuple in the relation.

Case-based online phone repair, please i request for your assistance in de...

please i request for your assistance in developing a case-based online phone repair

Describe the advantage of state chart diagram, Describe the advantage of St...

Describe the advantage of State chart Diagram A state chart represents a state machine, emphasizing flow of control from one state to other. A state machine is a behaviour whi

What functions does a data dictionary perform, What functions does a data d...

What functions does a data dictionary perform? In a (DBMS)data management system, the principal functions performed by the data dictionary are Management of data defini

Ordering of tuples, In a relation, tuples are not inserted in any definite ...

In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later accordin

Define the immediate update, Define the Immediate Update The immediate...

Define the Immediate Update The immediate update methods may apply changes to the database on disk before the transaction arrives a successful conclusion. Though, these change

HIT, Meaningful use refers to the use of certified EHR technology to "enhan...

Meaningful use refers to the use of certified EHR technology to "enhance quality, efficiency, and reduce health disparities

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