how to find minimum and maximum size ??

Question

R1(p,q,r)  and  R2(r,s,t) with the primary key P and R respectively.the relation R1 contain 200 tuple and R2 contain 250 tuple then minimum and maximum size find right outer join is........

Answer 1

Right outer join says that atleast all the tupples of right table should come. i think the minimum and max here will be 250 only. because first we will perform the natural join and take all right table tupples . R is the primary key of relation so natural join on both the table will result in 200 tupples but we have to take all the remaining right into consideration so it should be 250.

Answer 2

It will have few conditions:

For : R1 right_outer R2

Case-1: If each rows of R1 get only one matched row of R2 then result will be :250( bcz of right outer join)

Case-2: If rows of R1 doesn't get any matched row in R2 then result will be :250( bcz of right outer join)

For : R2 right_outer R1

Case-1: 200

Case-2: 200