1. An example: Find the names of all branches in the account relation.

select bname
from account

2. distinct vs. all: elimination or not elimination of duplicates.

Find the names of all branches in the account relation.

select distinct bname
from account

By default, duplicates are not removed. We can state it explicitly using all.

select all bname
from account

3. select * means select all the attributes. Arithmetic operations can also be in the selection list.