$sum is an accumulator operator available only in the _______ stage
A. $group
B. $sets
C. $accumulator
D. None of the mentioned
Answer:A
$sum is an accumulator operator available only in the _______ stage
A. $group B. $sets C. $accumulator D. None of the mentioned
Explanation:$sum calculates and returns the sum of all the numeric values. 2. Point out the wrong statement :