GROUP BY without aggregate function

Question

I am trying to understand GROUP BY (new to oracle dbms) without aggregate function.
How does it operate?
Here is what i have tried.

EMP table on

Answer 1

As an addition

basically the number of columns have to be equal to the number of columns in the GROUP BY clause

is not a correct statement.

• Any attribute which is not a part of GROUP BY clause can not be used for selection
• Any attribute which is a part of GROUP BY clause can be used for selection but not mandatory.