Differentiate sub-class and super-class, Database Management System

Assignment Help:

Differentiate sub-class and super-class?

The specialization of a class is known as subclasses.eg: employee is a subclass of person and teller is a subclass of employee. Conversely, employee is a super class of teller, and person is a super class of employee.  

 


Related Discussions:- Differentiate sub-class and super-class

Define shared locks, Define Shared locks? Ans: Shared lock: Throughout ...

Define Shared locks? Ans: Shared lock: Throughout concurrent execution of transactions, earlier than a transaction can access a data item, it has to obtain a lock on it. Now he

Which operation is used if we are interested certain columns, Which operati...

Which operation is used if we are interested in only certain columns of a table? PROJECTION operation is used if we are interested in only certain columns of a table.

List out user authorization to modify the database schema, List out various...

List out various user authorization to modify the database schema. a)  Index authorization b)  Resource authorization c)  Alteration authorization d)  Drop authorizat

What is multilevel index, Multilevel Index The Multilevel Index is a m...

Multilevel Index The Multilevel Index is a modification of the secondary level index system. In this system we might be use even more number of levels in case the table is eve

Define the division operation of relational algebra, Define the Division Op...

Define the Division Operation of Relational Algebra Let R be a relation comprising attributes (A1,...Ap,Ap+1,...An) and S comprising attributes (Ap+1,...An)  DEF: Division

Explain the timestamps for read operations, Timestamps For Read operations:...

Timestamps For Read operations: If TS (T) If TS (T) >= W-timestamp (Q), then the transaction T is trying to read a value of data item Q which has been written and committed

What subschema expresses, What subschema expresses ? A subschema expres...

What subschema expresses ? A subschema expresses the external view. (External schemas are called also called as subschemas)

What are the key features of oracle, What are the key features of Oracle? ...

What are the key features of Oracle? Key features of Oracle are as follows: • Read Consistency • Concurrency • Locking Mechanisms • Quiesce Database • RAC • Portability

Having clause with sub queries, Having Clause with sub queries: First we h...

Having Clause with sub queries: First we have to recollect the GROUP BYclause. The following query searches the minimum salary in every department. SELECT DEPTNO, MIN (SAL)

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd