Question

Point out the wrong statement.

(a) Some pipeline stages may generate new documents or filter out documents

(b) Pipeline stages do need to produce one output document for every input document

(c) Pipeline stages can appear multiple times in the pipeline

(d) None of the mentioned

This question was addressed to me by my college director while I was bunking the class.

Origin of the question is Aggregation Pipeline in section Aggregation Concepts and Aggregation Mechanics of MongoDB

Answer 1

Correct option is (b) Pipeline stages do need to produce one output document for every input document

To explain: Pipeline stages do need to produce one output document for every input document.