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

What is database trigger, What is database Trigger? A database trigger ...

What is database Trigger? A database trigger is a PL/SQL block that can explained to automatically execute for insert, update, and delete statements against a table. The trigge

ER diagrams, explain exhaustively the problems associated with ER diagrams....

explain exhaustively the problems associated with ER diagrams. include illustrations in your answer

Incident report to the database, The Form input elements are: ...

The Form input elements are: Reporter name text type input Password

File organisation, Define reference file

Define reference file

Sources of utilities for a dbms, There are three main sources of utilities ...

There are three main sources of utilities and applications for a DBMS: a. Vendor applications and utilities are given for working with or maintaining the database, and generally

Database, 3. (10 points) Assume that you have been presented with the follo...

3. (10 points) Assume that you have been presented with the following relation for the Baxter Aviation database: Charters (Pilot#, Pilot name, Aircraft ID#, #seats, Village, Fligh

Update operations in dbms - insert operation, Update Operations and Dealing...

Update Operations and Dealing with Constraint Violations There are three basic operations to be executes on relations: Insertion Deletion Update The INSER

What are costs to be considere when transaction is roll back, What are the ...

What are the costs to be considered when a transaction has to be rolled back when recovering from deadlock? Ans: A few transaction will must rolled back (made a victim)

Project, Preliminary entities and attributes of human resourse management d...

Preliminary entities and attributes of human resourse management database management system

What is vertical fragmentation, What is vertical fragmentation? Vertica...

What is vertical fragmentation? Vertical fragmentation divides the relation by decomposing the scheme R of relation r.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages