Hi Colleagues,
In fact system probably will not perform an "full scan" like in other databases, join engine is optimized to access most selective table first and read second based on findings of first. In such case it should lead to read 1 row of emp and 1 row for department.
This is probably an incorrect information from explain plain..
Perform an PlanViz and there check the number of rows returned by each table.
I did same test with 10million rows on each table and on PlanViz information was that one row was read from each table.
Regards, Fernando Da Rós