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 are the advantages of logical databases, What are the advantages of Lo...

What are the advantages of Logical Databases? It offers a simple-to-use selection screens. You can change the pre-generated selection screen to your needs. It offers check f

Determine the programming language structures, What is the most significant...

What is the most significant feature that does not directly map into programming language structures? Why? Association, since there are complex types of association, like as qu

What is rdbms, What is RDBMS? Relational Data Base Management Systems (...

What is RDBMS? Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be formed and

RAID technology, what characterizes the levels in RAID technology

what characterizes the levels in RAID technology

Explain the check clause, Explain the Check Clause The CHECK clause is ...

Explain the Check Clause The CHECK clause is employed to at the end of a CREATE TABLE statement specify table constraints. This is known as table-based constraint because it ap

Define partial key and primary key, Define Partial Key and Primary Key ...

Define Partial Key and Primary Key A partial key, also known as discriminator, is the set of attributes which can uniquely identify weak entities that are related to similar o

Database, . Ashutosh Dubey who is the director of Gyan Gurukul want a three...

. Ashutosh Dubey who is the director of Gyan Gurukul want a three-level schema architecture for the Gyan Gurukul Company that provide better security also design a data abstraction

Example-revoke all on emp from mca12, Example: //REVOKE ALL ON EMP FROM MC...

Example: //REVOKE ALL ON EMP FROM MCA12; (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-

What are wait-for-graphs, What are wait-for-graphs?Give the algorithm to co...

What are wait-for-graphs?Give the algorithm to construct a wait-for-graph from a given schedule of transactions? How can deadlocks be detected from wait-for-graphs? Ans: The

RDBMS, what is RDBMS? how it works? good example.

what is RDBMS? how it works? good example.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages