Explanation: For map-reduce operations, MongoDB provides the mapReduce database command. 2. Point out the wrong statement :
A. Map-reduce cannot have a finalize stage to make final modifications to the result
B. Map-reduce is less efficient and more complex than the aggregation pipeline
C. Specifically, a user with the userAdmin role can grant itself any privilege in the database
D. All of the mentioned
Answer:A
Explanation: For map-reduce operations, MongoDB provides the mapReduce database command. 2. Point out the wrong statement :
A. Map-reduce cannot have a finalize stage to make final modifications to the result B. Map-reduce is less efficient and more complex than the aggregation pipeline C. Specifically, a user with the userAdmin role can grant itself any privilege in the database D. All of the mentioned
Explanation:In general, map-reduce operations have two phases: a map stage that processes each document and emits one or more objects for each input document, and reduce phase that combines the output of the map operation. 3. MongoDB applies the _____ phase to each input document in mapreduce.