join

Question

Comment on the following two statements

• Natural Join produce cartecian product of two tables  on joing two relations with no matching coloums
• Full Outer Join produce cartecian product of two tables  on joing two relations with no matching coloums

Comments

first one is true

Answer 1

Both are true:

1st statement) natural join is cartesian cross product with intersection of columns taken over the result

2nd statement) first take natural join. Then add the tuples from the left table to the result which didnt match with any tuple in right table.Then add the tuples from the right table to the result which didnt match with any tuple in left table.

Finnaly, both are natural joins. So no matching columns.