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

Databases and data warehouses , Databases and data warehouses both are data...

Databases and data warehouses both are databases and both contains number of rows and columns of tables containing data. Data warehouse is really different from databases because d

Create a customer database and apply queries, For the question given below,...

For the question given below, you are required to submit design and implementation documentation as described over the page. Design, implement (in Java), test and document a set of

Explain the attribute inheritance, Explain the Attribute inheritance An...

Explain the Attribute inheritance Ans: Throughout the rendering of the objects in a view, attribute sets of objects higher in the view hierarchy are inherited via objects below

Explain what is relation, Explain What is Relation? A database relatio...

Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.

Define lock, Define lock? Lock is the most common used to execute the r...

Define lock? Lock is the most common used to execute the requirement is to permit a transaction to access a data item only if it is currently holding a lock on that item.

Write the sql queries using data manipulation language, Problem 1. Writ...

Problem 1. Write the SQL queries using Data Manipulation Language (DML) statements. Insert values into student table with field names using insert command Display the

Security-drawbacks of data distribution, Security: In a centralised system...

Security: In a centralised system, access to the data can be simply controlled. Though, in a distributed DBMS not only does access to replicated data have to be controlled in many

What is a state chart diagram, What is a state chart diagram? State dia...

What is a state chart diagram? State diagrams (State Chart Diagram) explain all possible states that a particular object can get into, and how object's state changes as result

Explain the exec statement in sql, Explain the EXEC statement in SQL  A...

Explain the EXEC statement in SQL  Ans: All statements which start with EXEC SQL are embedded SQL database statements. High level languages such as C can be employed to write a

Extended star schema, Why did SAP introduce the extended star schema? Expla...

Why did SAP introduce the extended star schema? Explain why it is reported to be better than the traditional schema model?

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