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

Objectives of data management, The traffic data mgmt. systems infrastructur...

The traffic data mgmt. systems infrastructure plan describes the software, hardware, data network, and other elements that will support the TDMS. The infrastructure plan is based o

User error-database errors, User error :  This contains errors in the progr...

User error :  This contains errors in the program (e.g., Logical errors) with errors made by online users of database.  These types of errors can be avoided by applying some check

Explain trigger, Explain trigger? Trigger: A database trigger is proc...

Explain trigger? Trigger: A database trigger is procedural code which is automatically executed within response to certain events on a particular table in a database. Trigger

What do you mean by correlated subquery, What do you mean by Correlated sub...

What do you mean by Correlated subquery? Subqueries, or nested queries, are used to bring back a set of rows to be used by the parent query. Depending on how the subquery is writ

What is a hashing function, What is a hashing function?  What are the prope...

What is a hashing function?  What are the properties of a good hashing function?  Describe the folding technique for hashing functions.      Ans:  Hashing function is a method

What is called an evaluation primitive, What is called an evaluation primit...

What is called an evaluation primitive? A relational algebra operation annotated with instructions on how to evaluate is known as an evaluation primitive.

Mention the purpose of sid and sod lines, Mention the purpose of SID and SO...

Mention the purpose of SID and SOD lines SID (Serial input data line): It is an input line by which the microprocessor accepts serial data. SOD (Serial output data line)

Data analyzing and desing, Critically explained the benefits and limit...

Critically explained the benefits and limitations of different database technologies with proper examples

RDBMS, Benefits and limitations

Benefits and limitations

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