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

Sql queries, find a name whose address is erode from student table

find a name whose address is erode from student table

single products ordered, For Colorado customers calculate the number of si...

For Colorado customers calculate the number of single products ordered. If a product is purchased on multiple orders, it should be counted only single time. The result should conta

Explain candidate key and super key, Explain Candidate Key and Super Key ...

Explain Candidate Key and Super Key A super key is a set of one or more than attributes that, taken collectively, permits us to identify uniquely a tuple in the relation. Wher

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

Explain embedding sql statements, Question 1 Explain the functions of t...

Question 1 Explain the functions of the following Storage Manager Buffer Manager Transaction Manager 2 Discuss about system catalog in a relational DBMS 3

Explain two phase locking protocol, Explain Two phase locking protocol ...

Explain Two phase locking protocol A transaction is consider as to follow the two-phase locking protocol if all locking operations precede the first unlock operation in the tra

Oracle fusion middleware, Oracle Fusion Middleware: Key Skills: Consul...

Oracle Fusion Middleware: Key Skills: Consulting,Architect, Oracle Fusion Middleware,ECM, UCM, Stellent,Identity Management, SOA Suites, BPEL, ESB,OAM,OIM,J2ee, Java, Livelink

Identify the candidate keys, Consider the following six relation schemes an...

Consider the following six relation schemes and their corresponding sets of functional dependencies. In each case identify a. All the candidate keys b. The highest normal for

Define decision tree classifiers, Define decision tree classifiers? As ...

Define decision tree classifiers? As the name suggests decision tree classifiers use a tree: Every leaf node has an associated class, and every internal node has a predicate as

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