How can we apply the following scenario:
data_set_1 has a key column and several columns. data_set_2 has an identical structure of data_set_1. We want to
- what common keys among them.
- what different keys among them in two direction. data_set_1 - data_set_2 and data_set_2 - data_set_1.
- compare between each column in data_set_1 with its mirror in data_set_2.