Joined Relations Join operations take two relations and return as a result another relation. A join operation is a Cartesian product which requires that tuples in the two relations match(under some condition).It also specifies the attributes that are present in the result of the join The join operations are typically used as subquery expressions in the from clause ■Three types of joins: ·Natural join 。Inner join Outer join Database System Concepts-7th Edition 4.3 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 4.3 ©Silberschatz, Korth and Sudarshan th Edition Joined Relations ▪ Join operations take two relations and return as a result another relation. ▪ A join operation is a Cartesian product which requires that tuples in the two relations match (under some condition). It also specifies the attributes that are present in the result of the join ▪ The join operations are typically used as subquery expressions in the from clause ▪ Three types of joins: • Natural join • Inner join • Outer join