GATE | GATE-CS-2016 (Set 2) | Question 62
Consider the following database table named water_schemes :
The number of tuples returned by the following SQL query is
with total(name, capacity) as
select district_name, sum(capacity)
from water_schemes
group by district_name
with total_avg(capacity) as
select avg(capacity)
from total
select name
from total, total_avg
where total.capacity >= total_avg.capacity
(A) 1
(B) 2
(C) 3
(D) 4
Answer: (B)
Explanation: First group by district name is performed and total capacities obtained as following
Ajmer 20
Bikaner 40
Charu 30
Dungargarh 10
Then average capacity is computed,
Average Capacity = (20 + 40 + 30 + 10)/4
= 100/4
= 25.
Finally districts with more than average are selected.
Bikaner is 40 which is greater than average (25)
Charu is 30 which is also greater than average (25).
Therefore answer is 2 tuples.
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Last Updated :
28 Jun, 2021
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