Natural join is an additional operation in relational algebra, it can be replaced by which set of the following operations equivalently :
A.Select, Project
B.Cartesian-Product, Project
C.Cartesian-Product, Select, Project
D.Cartesian-Product, Select
- · 有5位网友选择 B,占比50%
- · 有3位网友选择 A,占比30%
- · 有2位网友选择 C,占比20%