Explain nested relations, Database Management System

Assignment Help:

Explain nested relations?

Nested relations

The assumption of INF is a natural one in the bank examples we have considered.

However, not all applications are best modelled by INF relations.

The nested relational model is an extension of the relational model in which domains might be either atomic or relation valued.

We illustrate nested relations by an example from a library. Assume we store for every book the following in formations

 Book title

Set of authors

Publishers

Set of keywords

We can see that if we describe a relation for the preceding information, several domains will be monatomic

Authors

Keywords

Publishers

Complex types

Collection and large object types

Create table books(

...

Keyword-set setoff(varchar(20))

           ...

            )

            Structure types

            Creation of values of complex types

 


Related Discussions:- Explain nested relations

Define assertions in sql, Define Assertions in SQL a. An assertion is a...

Define Assertions in SQL a. An assertion is a predicate that is expressing a condition we wish the database to always satisfy.  b. Domain constraints, functional dependency

System Analysis and design, Using the questions found at the end of Chapter...

Using the questions found at the end of Chapter 9 in your textbook, complete this homework activity. Students will submit a Word document answering questions 2, 3, and 4.

DW, #ques Define a job scheduling strategy that will meet business requirem...

#ques 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 p

What is the use of sub queries, What is the use of sub queries? A sub q...

What is the use of sub queries? A sub query is a select-from-where expression that is nested with in another query. A common use of sub queries is to do tests for set membershi

System level permissions-data control, System level permissions : With the ...

System level permissions : With the use of data dictionary you can view them.       Let us take the table name as user_sys_privs (used in oracle).       DESCRIBE USER_SYS_PRI

Explain how you can define an object model of a system, Explain how you can...

Explain how you can define an object model of a system. A list of terms that shall be used by end users to describe state and behaviour of objects in system.   Different use

Explain the disadvantages of creating a temporary table, Explain the disadv...

Explain the disadvantages of creating a temporary table? If you have already created a temporary table with a shown name and attempting to create a second one with that nam

Cases of constraint violations, (1)     Insert into PERSON Violated con...

(1)     Insert into PERSON Violated constraint: - Key constraint Reason: - Primary key 1 already exists in PERSON. Dealing: - DBMS could ask the user to provide valid PER

Describe the functions and features of foreign key, Describe the functions ...

Describe the functions and features of foreign key? Foreign Key : The primary key of one file or table that is implanted in another file or table to implement the relationships

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