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

Express the subsequent query in sql assumes, Express the subsequent query i...

Express the subsequent query in SQL assumes which the data is stored within EMPLOYEE table with relevant fields (i) Display name, job, salary, and hire date of employee who are

What are advantages of using an index and disadvantages, What are the advan...

What are the advantages of by using an index and what are its disadvantages ? In difference, if the search key of a secondary index is not a candidate key, it is not sufficient

Oracle RDBMS, compare the features of oracle RDBMS with MySQL and Microsoft...

compare the features of oracle RDBMS with MySQL and Microsoft SQL server

Describe the algorithm for updating indices, Describe the algorithm for upd...

Describe the algorithm for updating indices for a single level index when a record is (i) Inserted (ii) deleted What will be the modification if there are multilevel in

Define the terms ddl and dml, Define the terms i) DDL ii) DML DDL: Data...

Define the terms i) DDL ii) DML DDL: Data base schema is particular by a set of definitions expressed by a special language known as a data definition language. DML: A data

Distributed and client server databases, Distributed And Client Server Data...

Distributed And Client Server Databases Introduction This unit tells the distributed database systems which are primarily relational and one important execution model: the

What is a phantom deadlock, What is a Phantom Deadlock? In distributed...

What is a Phantom Deadlock? In distributed deadlock detection, the delay in propagating local information might cause the deadlock detection algorithms to recognize deadlocks

Want massive amount of products imported through csv, OPENCART - Want Massi...

OPENCART - Want Massive amount of products Imported through CSV We have a massive list of products that would take completely too long to do data entry. We require a slick progr

Write a short note on built in function in qbe, Write a short note on built...

Write a short note on built in function in QBE? Built in function in QBE: QBE involves various built in functions like AVG, MAX,MIN,SUM and CNT. We must prefix these operator

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

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages