CODEWITHSUNDEEP
databaserelational-databasenatural-join
noobcoder
noobcoder

Reputation: 160

Non-First Normal Form natural join operation

I have 2 tables in non-first normal form:

enter image description here

What would be the result of the NATURAL JOIN operation of these two table?

Upvotes: 0

Views: 172

Answers (1)

nvogel
nvogel

Reputation: 25524

It is not exactly clear what your picture is supposed to represent. I'm going to assume that R1 is a relation with three attributes, A,B and X; R2 is a relation with three attributes, E,B and X.

The natural join would be a join where the values in B and X are equal in both R1 and R2. What type of attribute is X? If X is a relation-valued attribute and the columns labelled C and D represent the tuples in X then it seems that the relation values are different in each case. (X in R1 and X in R2 happen to have some of the same tuple values in common but the values of relation X are different in each case).

So the result of the natural join would be an empty relation with a heading of A,B,E,X but with zero tuples.

Upvotes: 1

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