Consider relational schema and construct algebra query, Database Management System

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)

Posted Date: 5/10/2013 1:43:19 AM | Location : United States







Related Discussions:- Consider relational schema and construct algebra query, Assignment Help, Ask Question on Consider relational schema and construct algebra query, Get Answer, Expert's Help, Consider relational schema and construct algebra query Discussions

Write discussion on Consider relational schema and construct algebra query
Your posts are moderated
Related Questions
What is object containment? References among objects can be used to model dissimilar real-world concepts.

Explain weak and strong entity sets? Weak and Strong entity sets: A physically powerful entity set has a primary key. All tuples in the group are distinguishable through that k

What is aggregate function? Briefly describe it? Aggregate functions are functions that take a collection of values as input and return a one value. SQL offers 5 built-in aggre

What is SQL, and why is it important? SQL stands for Structured Query Language, and is the most significant data processing language in use today. It is not a complete programm

Command Line Interfaces: These are interactive interfaces, character-based that let you use the complete power and functionality of the DBMS query language directly. They permit yo


Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.

Which database level is closest to the users? External database level is closest to the users.

Database Management Systems 1. Explain SQL Server 2000 Architecture with diagram. 2. Describe Second Normal and Third Normal Form. 3. Explain about query engine and stora

What is the difference between WHERE and HAVING clauses?. Predicates in the WHERE clause applies to every tuple while the predicate in the HAVING clause applies to groups.