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

Enumerate about the high-level transitions result, Show, with the help of a...

Show, with the help of an example, that relatively high-level transitions result when system or program is stimulated by the outside events. In diagram below, we can observe i

Define 3nf normal form, 3NF Normal Form A relation schema R is in 3NF ...

3NF Normal Form A relation schema R is in 3NF if it is in 2NF and for each FD X A either of the following is true X is a Super-key of R. A is a prime attribute of R

Physical location of record is determined by which formula, The physical lo...

The physical location of a record is determined by which mathematical formula that transforms a file key into a record location? The physical location of a record is determined

Cataloguing, differences between a classified catalog and a dictionary cata...

differences between a classified catalog and a dictionary catalog

Each statement should have a where clause, Submit SQL SELECT Statements to ...

Submit SQL SELECT Statements to demonstrate several reports off your database, according to the following guidelines: You must submit at least 5 SELECT Statements. Each

Search the salary of employees who are not ‘analyst’ , Example- Search the ...

Example- Search the salary of employees who are not 'ANALYST' but get a salary below than or equal to any people employed as 'ANALYST'. SELECT EMPNO, ENAME, JOB, SAL FROMEMP

What is known as clustering file organization, What is known as clustering ...

What is known as clustering file organization? In the clustering file organization, records of several dissimilar relations are stored in the similar file.

Define sequence, Define Sequence A sequence is a set of integers 1, 2, ...

Define Sequence A sequence is a set of integers 1, 2, 3 that are generated in order on demand. Sequences are regularly used in databases because lots of applications require ev

Visio diagram - database, The database depicted in the Visio diagram descri...

The database depicted in the Visio diagram describes Proceeding , Article , Researcher , article PublishedIn a proceeding, article WrittenBy researchers and proceedings Edi

What are domain constraints, What are domain constraints? A domain is a...

What are domain constraints? A domain is a set of values that might be assigned to an attribute .all values that appear in a column of a relation must be taken from the similar

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