What is inheritance, Database Management System

Assignment Help:

What is inheritance? Define it in detail?

 Inheritance

Inheritance can be at the levels of types, or at the level of tables we first consider inheritance of types, then inheritance at the level of labels.

Type inheritance

Assume that we have the following type definition for people

create type person

(name varchar(20)

address varchar(20))

Table inheritance

Create table people of person

The consistency requirements for sub tables are

1. Each tuple of the sub table can correspond to at most single tuple in each of its immediate sub tables.

2. SQL:1999 has an additional constraint that all the tuples corresponding to each other must be derived from single tuple .

 


Related Discussions:- What is inheritance

Draw an e-r diagram and convert it to a relational schema, In an organisati...

In an organisation various projects are undertaken. Each projects can employ one or more employees. Every employee can work on one or more projects. Each project is undertaken on

Equi-join, explain equi-join using illustration

explain equi-join using illustration

What is meant by object-oriented data model, What is meant by object-orient...

What is meant by object-oriented data model? The object-oriented paradigm is based on encapsulation of data and code related to an object in to a one unit, whose contents are n

Mis, explain three types of internet risks to the consummers whent he busin...

explain three types of internet risks to the consummers whent he business system is data dependent. how can we minimise these risks

How to insert data in your table from another table, How to Insert data in ...

How to Insert data in your table from another table? insert into e.g, To insert tuples from employee into N_emp created above, use following statement Insert into N_emp

Write modified version of transfer that avoids deadlock, Your OS has a set ...

Your OS has a set of queues, each of which is protected by a lock. To enqueue or dequeue an item, a thread must hold the lock associated to the queue. You need to implement an a

Need senior oracle database administrator, Project Description: Oracle C...

Project Description: Oracle Certified Professional with 20 years of practice, Oracle version 6.0.34, 7.3, 8.0, 8i, 9i, 10G, 11G, 12C. Crossplatform migration, Informix, MSSql

Develop motel point of sale software, Project Description: I need a poin...

Project Description: I need a point of sale for motels. It needs to run on windows and requires being network able so that we can have more than one computer using it at once.

What is a homogeneous distributed database, What is a homogeneous distribut...

What is a homogeneous distributed database? In homogeneous distributed databases, all sites have the same database management system software, are aware of one another, and agr

Objectives-database recovery and security, Objectives Define the te...

Objectives Define the terms RECOVERY and INTEGRITY; Define Recovery Techniques; Explain Error and Error detection techniques, and Define types of Authorisation.

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