Select the correct statement :

MongoDB scales horizontally using _________ for load balancing purpose.

Point out the wrong statement :

MongoDB supports fixed-size collections called ____________ collections.

____________ are operations that process data records and return computed results.

Select the wrong statement :

Running data aggregation on the ________ instance simplifies application code and limits resource requirements.

Documents enter a multi-stage __________ that transforms the documents into an aggregated result.

Map-reduce uses custom __________ functions to perform the map and reduce operations.

Which of the following operation can be optionally used for map reduce ?