Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique?

All of the attributes are sent from one site to another and then only the required rows are returned.

Only the joining attributes are sent from one site to another and then all of the rows are returned.

Only the joining attributes are sent from one site to another and then only the required rows are returned.

Semi-join strategies are techniques for query processing in distribute

1.	Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique?
A.	Only the joining attributes are sent from one site to another and then all of the rows are returned.
B.	All of the attributes are sent from one site to another and then only the required rows are returned.
C.	Only the joining attributes are sent from one site to another and then only the required rows are returned.
D.	All of the attributes are sent from one site to another and then only the required rows are returned.
Answer» D. All of the attributes are sent from one site to another and then only the required rows are returned.