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

DW Job Scheduling, Define a job scheduling strategy that will meet business...

Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori

Describe the static hash file with buckets and chaining, Describe the stati...

Describe the static hash file with buckets and chaining and show how insertion, deletion and modification of a record can be performed. In static hash file organization, the wo

Explain normalization, What is Normalization? Database normalization is...

What is Normalization? Database normalization is a data design and organization method applied to data structures based on rules that help building relational databases. In rel

Write short notes on index structure of files, WRITE SHORT NOTES ON INDEX S...

WRITE SHORT NOTES ON INDEX STRUCTURE OF FILES? There are two basic parts of indices 1.   Ordered indices 2.   Hash indices Every technique must be evaluated on the bas

Database project- inventory database for a hardware store, Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

The basic 2pl-two phase locking (2pl), Normal 0 false false ...

Normal 0 false false false EN-US X-NONE X-NONE

What are composite attributes, What are composite attributes? Composite...

What are composite attributes? Composite attributes can be separated in to sub parts.

Describe the nested-loop join and block-nested loop join, Describe the nest...

Describe the nested-loop join and block-nested loop join.   Ans:   The block nested- loop join algorithm is as described below:     for every block B r of relation R do beg

Conversion of er diagram to relational database, Conversion of entity sets:...

Conversion of entity sets: I)   For  every  strong  entity  type  E  in  the  ER  diagram,  we  make  a  relation  R containing all the easy attributes of E. The relation R pri

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