- Which of the following creates temporary relation for the query on which it is defined ?
- The EXISTS keyword will be true if:
- Which of the following relational algebra operations do not require the participating tables to be union-compatible?
- Which of the following operations need the participating relations to be union compatible?
- Select name from instructor where salary <=100000 and salary >=90000;
This query can be replaced by which of the following ? - Select __________
from instructor
where dept name= ’Comp. Sci.’;
Which of the following should be used to find the mean of the salary ? - Aggregate functions are functions that take a ___________ as input and return a single value
With
From
Where
Select
Any row in the subquery meets the condition only.
All rows in the subquery fail the condition only.
Both of these two conditions are met.
Neither of these two conditions is met.
Union
Insertion
Difference
Join
Union
Insertion
Difference
All the above
Select name
from instructor
where salary between 90000 and 100000;
Select name
from employee
where salary <= 90000 and salary>=100000;
Select name
from employee
where salary between 90000 and 100000;
Select name
from instructor
where salary between 100000 and 90000;
Mean(salary)
Count(salary)
Avg(salary)
Sum(salary)
Collection of values
Single value
Aggregate value
Both a & b
