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

What is the need of a log in a dbms, What is the need of a log in a DBMS? B...

What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log.            Ans:  The system log, which is generally writt

Define the relations as tables in sql, Consider the relations given below ...

Consider the relations given below Borrower (id_no, name) Book (accno., title, author, borrower_idno) (a) Define the above relations as tables in SQL forming real world assumptio

Time stamp ordering, explain in detail about time stamp orderting/

explain in detail about time stamp orderting/

What is bucket overflow and how bucket overflow is handled, What is bucket ...

What is bucket overflow and how bucket overflow is handled through Over Flow Chaining or Closed Hashing? Ans: Bucket: unit of storage holding records. Bucket is a disk block

How does the two phase protocol ensure serializability, How does the two ph...

How does the two phase protocol ensure serializability in database schedules?   Ans:  A transaction is termed to follow the two-phase locking protocol if all locking operations

Creation of indexes, Creation of Indexes Automatically: When a primar...

Creation of Indexes Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically. Manually: User can

Define cardinality and participation constraints, Define cardinality and pa...

Define cardinality and participation constraints on a relationship type, completeness constraint on generalization.        Ans: Cardinality defines the number of entities to wh

OLD HOME POLICIES, Write an sql statement to find what is the percentage of...

Write an sql statement to find what is the percentage of home policies which are from the state of Arizona out of all Home policies by Policy Value.

Use inheritance as an implementation technique, Use inheritance as an imple...

Use inheritance as an implementation technique when you are going to use inheritance as an implementation technique, you can achieve same goal in a safer way by making one cla

Database, A database has been designed for this beauty parlour in order for...

A database has been designed for this beauty parlour in order for the staff to manage specific things such as bookings made by clients, payments, staff availability, level of exper

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