In the context of this exercise, what does a
CROSS JOIN do?
CROSS JOIN function returns a Cartesian product of all the rows from the first table, with all rows of the second table. As a result, if there are
M rows in the first table, and
N rows in the second table, then there will be a total of
M x N rows in the result. Each row from the first table will be combined with each row from the second table.
For example, if the tables were as follows,
table 1 x1 x2 x3 table 2 y1 y2 y3
Then the result of applying
CROSS JOIN to these would be
x1 y1 x1 y2 x1 y3 x2 y1 x2 y2 x2 y3 x3 y1 x3 y2 x3 y3