The following questions are based on the tables test1:

select * from test1;

tt | discount

------------------------------------

14 | 0.00

9999 | 0.00

10 | 22.22

11 | 0.00

null | 11.00

(5 rows)

Write down the results of executing the following

1) select count(*) from test1;

2) select count(tt) from test1;

3) select count(distinct discount) from test1;

4) select avg(tt) from test1;

5) select avg(distinct discount) from test1;

6) select * from test1 t1 natural inner join test1 t2;