Cartesian product, Database Management System

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If R1 and R2 are two relations or functions, then the result of R3 = R1 × R2 is the combination of tuples that are in R1 and R2. The product is associative and commutative.

Degree (R3) =Degree of (R1) + Degree (R2).

In case, R3 will have tuples such that R3 = {t1 || t2 | R1 ∋ t1  ∧ R2 ∋ t2}.

Example:

R2

A

B

A1

B1

A2

B2

A3

B3

A4

B4

 

 

       R1                         

C

C1

C2

 
       

R3 = R1 × R2 is

 

A

B

C

A1

B1

C1

A1

B1

C2

A2

B2

C1

A2

B2

C2

A3

B3

C1

A3

B3

C2

A4

B4

C1

A4

B4

C2

 


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