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

Shadow copy, why shadow copy technique is used?

why shadow copy technique is used?

Explain the form of the create view command, We define a view in SQL throug...

We define a view in SQL through using the create view command. To describe a view, we must provide the view a name and must state the query in which computers the view. The form of

Data warehouse, XYZ is a large chain of home entertainment rental over 100 ...

XYZ is a large chain of home entertainment rental over 100 stores distributed over all states in Australia. XYZ lends entertainment products such as movies, TV shows and games on v

Determine the minimal set of functional dependencies, Determine the minimal...

Determine the minimal set of functional dependencies for the following data. This table is part of the OHSU database of extracurricular activities and tracks the DMICE band's co

Create database for car application, The Database MySQL scripts cars_f...

The Database MySQL scripts cars_for_sale.sql and car_details.sql containing the data to use for this task have been supplied. To complete this task, you need to first create

Explain thomas write rule, Explain Thomas' Write rule. Show how it is diff...

Explain Thomas' Write rule. Show how it is different from timestamp ordering protol Ans: In timestamp-based concurrency control the thomas Write rule is a rule. Given a Timest

Define clause in sql to specify query result must be sorted, The clause in ...

The clause in SQL which specifies that the query result should be sorted in ascending or descending order based upon the values of one or much more columns is Ans : Order by

What is a sub-query, (a) What is a Sub-Query? (b) What is the differen...

(a) What is a Sub-Query? (b) What is the difference between a scalar sub-query and a tabular sub-query? (c) Write an equivalent SQL statement to get the Name of Product wh

Why are cursors necessary in embedded sql, Why are cursors necessary in emb...

Why are cursors necessary in embedded SQL? A cursor is an object used to store the output of a query for row-by-row processing through the application programs. SQL statements

Calculate the record size r in bytes, An employee record has the following ...

An employee record has the following structure struct employee { int eno; char name[22]; float salary; char dept[10];}; (i) Calculate the record size R in bytes.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages