Final answer:
Natural join combines tables based on common attributes. For R(A, B, C, D) and S(A, C, E), the result is RMS(A, B, C, D, E). For R(A, B) and S(A, B), the result is simply RS(A, B) without duplication of attributes.
Step-by-step explanation:
The question relates to the operation of a Natural Join in database management systems, specifically within the context of relational database schemas. A Natural Join combines tables based on their common attributes.
Schema of RMS:
Given the schemas R(A, B, C, D) and S(A, C, E), the schema of RMS (the result of the natural join) would be RMS(A, B, C, D, E). The common attribute columns A and C from both R and S are used to join, and are included only once.
Schema of RS:
Given the schemas R(A, B, C) and S(D, E), RS (the result of a cross product since there are no common attributes) would be RS(A, B, C, D, E), simply appending the attributes of S to R's because no natural join is possible.
Given R(A, B) and S(A, B), the schema of RS would be RS(A, B), as A and B are common in both tables and a natural join would combine them based on these columns without duplication.