 The cardinality of the number of rows in the relation. The number in C ranges from the number in A times the number in B all the way to 0.

close The cardinality of the number of rows in the relation. The number in C ranges from the number in A times the number in B all the way to 0.

close The arity is the number of columns in the relation. In relational algebra, all columns of the relations are kept, and thus the arity of C is the arity of A plus B. The arity of both A and B must be greater than one.

close The arity is the number of columns in the relation. In relational algebra, all columns of the relations are kept, and thus the arity of C is the arity of A plus B. The arity of both A and B must be greater than one.

close The cardinality of the number of rows in the relation. The number in C ranges from the number in A times the number in B all the way to 0. The arity is the number of columns in the relation. In relational algebra, all columns of the relations are kept, and thus the arity of C is the arity of A plus B. The arity of both A and B must be greater than one.

close

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Relation C is the join of relation A and relation B on condition p. Which of the following statements must be true in all cases?

1. The cardinality of C is greater than the cardinality of A
2. The cardinality of C is less than the cardinality of A
3. The arity of C is greater than the arity of A
4. The arity of C is less than the arity of A
5. None of the above