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

Relation instance or relation state, A relation instance indicates as r is ...

A relation instance indicates as r is a collection of tuples for a given relational schema at a exact point of time. A relation state r of the relation schema R (A 1 ,A 2 ,.....

Outer join, Outer Join: The use of Outer Join is that it still joins those...

Outer Join: The use of Outer Join is that it still joins those tuples that do not have matching values in common columns are also contained in the result table. Outer join places

Define data independence, Data independence seems that "the application is...

Data independence seems that "the application is independent of the access strategy and storage structure of data". In other words, the ability to change the schema definition in o

Operator precedence-data manipulation language, Operator Precedence The...

Operator Precedence The basic operators used in SQL are * / - + Operators of the similar priority are evaluated From Left to right Parentheses are used to force priorit

Descrine an data dictionary, Describe an data dictionary? A data dictio...

Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.

Relationship between two tables-strategic decision making, In a job intervi...

In a job interview with a branch manager of a bank that operates in multiple Canadian provinces and the Yukon, you learn that all of the information is captured in real time in a s

Mapping, external and internal mapping with examples

external and internal mapping with examples

Dml precompiler in database management system, DML Precompiler All th...

DML Precompiler All the DBMS have two basic sets of Languages - Data Definition Language (DDL) that have the set of commands needed to define the format of the data that is b

Find the employee name, Example -Find the employee name, salary, department...

Example -Find the employee name, salary, department number and average salary of his/her department, for those employees whose salary is more than the average salary of that depart

What features relational dbms contribute level of integrity, A well-maintai...

A well-maintained relational DBMS has a high level of data integrity. What features of a relational DBMS contribute towards this level of integrity? Relational DBMS gives high

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages