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

Natural join-table handling, Natural Join : It is the similar like Equi joi...

Natural Join : It is the similar like Equi join except one of the duplicate columns is removed in the result table. The natural join is the most usually used form of join operation

Optimistic concurrency contents -write-set(t), write-set(T): Each data ite...

write-set(T): Each data items that are written by a transaction T

Sql, Events4Fun is an event management company in Europe with branches in S...

Events4Fun is an event management company in Europe with branches in South America as well. The company is well-known for its efficiency, good-quality services, and affordable char

What are the advantages of dbms, What are the advantages of DBMS ? 1. ...

What are the advantages of DBMS ? 1. Centralized Management and Control - One of the major advantages of using a database system is in which the organization could exert, thr

Explain the term- event, Event Occurrence of a process is called event...

Event Occurrence of a process is called event. In other words, the object can receive many input instructions. The changes which occur due to these instructions are known as e

What are advantages of object-oriented programming paradigm, What is the ma...

What is the major advantage of object-oriented programming paradigm? The ability to modify the explanation of an object without affecting the rest of the system is the main adv

Related fields in a database are grouped in which form, Related fields in a...

Related fields in a database are grouped in which form? Related data fields in a database are grouped to form a data record. (A record is a collection of related fields)

What is a heterogeneous distributed database, What is a heterogeneous distr...

What is a heterogeneous distributed database? In a heterogeneous distributed database, dissimilar sites may use different schemas, and dissimilar dbms s/w. The sites may not be

Name the three major database in oracle, Name the three major set of files ...

Name the three major set of files on disk that compose a database in Oracle. There are three main sets of files on disk that compose a database. All the files are binary. These

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