$20-$ The statement below is erroneous because select dept name, dept$\_$id$,$ avg$($salary$)$ from instructor group by dept$\_$name;

a$)$ avg$($salary$)$ is invalid

b$)$ group by clause is not valid in this query

c$)$ misplaced group by clause

d$)$ dept name should not be selected

e$)$ dept id should not be selected

$21-$ Which of the following creates a temporary relation for the query on which it is defined?

a$)$ where

b$)$ from

c$)$ with

d$)$ select

e$)$ none of them

$22-$ In the query below which one of the following is a temporary relation?

with max$\_$budget $($value$)$ as $($select max$($budget$)$ from department$)$

select budget from department, max$\_$budget where department.budget $=$ max$\_$budget.value:

a$)$ budget

b$)$ department

c$)$ value

d$)$ select

e$)$ max$\_$budget

$23-$ Which of the following is not an aggregate function?

a$)$ avg

b$)$ sum

c$)$ with

d$)$ min

e$)$ max

$24-$ The command "delete from r where P;$"$

a$)$ deletes tuple$($s$)$

b$)$ deletes relation

c$)$ deletes attribute

d$)$ all of them

e$)$ none of them

$25-$ Which one of the following deletes all the entries but keeps the structure of the relation?

a$)$ delete from $r$ where $P$;

b$)$ delete from instructor where dept name$=$ 'Finance';

c$)$ delete from instructor where salary between $13000$ and $15000$ ;

d$)$ delete from instructor;

e$)$ none of them

$26-$Find the keyword to update the instructor relation by "update instructor salary $=$ salary $*1\mathrm{.}05$;

a$)$ where

b$)$ set

c$)$ in

d$)$ select

e$)$ write

$27-$ The problem of ordering the update in multiple updates is avoided using

a$)$ set

b$)$ where

c$)$ case

d$)$ when

e$)$ with

$28-$The condition allows a general predicate over the relations being joined.

a$)$ with

b$)$ using

c$)$ set

d$)$ on

e$)$ where

$29-$ The query below is equivalent to

select $*$ from student join takes using$($ID$)$;

a$)$ select from student inner join takes using$($ID$)$;

b$)$ select from student outer join takes using$($ID$)$;

c$)$ select from student left outer join takes using$($ID$)$;

d$)$ select from student right outer join takes using$($ID$)$;

e$)$ none of the above