Intersection, Database Management System

Assignment Help:

If R1 and R2 are two union compatible relations or functions, then the result of R3 = R1 ∩R2 is the relation that contains all tuples that are in both the relations In other words, R3will have tuples such that R3 = {t | R1 ∋ t ∧ R2 ∋ t}.

Example:

 

 R1

A

B

A1

B1

A2

B2

A3

B3

A4

B4

  R2                     

A7

B7

X

Y

A1

B1

A7

B7

A2

B2

A4

B4

 

R3 = R1 ∩ R2 is

 

 

R3 = R1 ∩ R2 is

A

B

A1

B1

A2

B2

A4

B4

 

Note: 1) Intersection is an associative operation, i.e., R1 ∩ (R2 ∩ R3) = (R1 ∩ R2) ∩ R3

2) Intersection is a commutative operation, i.e., R1 ∩ R2 = R2 ∩ R1


Related Discussions:- Intersection

Domains, A domain is a set of permissible values that can be given to an at...

A domain is a set of permissible values that can be given to an attribute. So each attribute in a table has a definite domain. Values to these attributes cannot be assigned outside

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

How can redundant associations be done, How can Redundant Associations be d...

How can Redundant Associations be done It can be done by asking questions: i)  Is there a specific arrangement of network which would optimize critical aspects of completed

Seeking hr searcher, Project Description: The work is about founding the...

Project Description: The work is about founding the best skilled person for the job. I will give you the job description. Skills required are Data Entry, Database Administrat

Explain the b+ tree, Explain the B + tree? B + tree is a type of tre...

Explain the B + tree? B + tree is a type of tree which denotes sorted data in a way that permits for efficient insertion, retrieval and removal of records, each of which is

Whst is logical schema, Whst is logical schema ? Logical schema is the ...

Whst is logical schema ? Logical schema is the entire database.

Relational database, Convert the following ER - diagram (Entity Relationsh...

Convert the following ER - diagram (Entity Relationship Diagram) into a relational database (the primary keys are underlined): 2160_Convert the following ER - diagram into a

Create role named roletable to allows a user to create table, Create role n...

Create role named role_table that allows a user to create tables. Using role_table allow users kripa and reena to create tables. CREATE ROLE role_table; GRANT CREATE ANY TABLE

What are the various states of transaction process, What are the various st...

What are the various states through which a transaction passes through in its lifetime?  Briefly discuss all the events that causes transition from one state to another.   Ans:

Online Bakery Data Base Project, How much would you charge to create a data...

How much would you charge to create a database encompassing an Online Bakery with all the elements below? I. Describe the application that you would like to design. This should

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