class Mongo::Operation::Commands::MapReduce
A MongoDB map reduce operation.
@note A map/reduce operation can behave like a read and
return a result set, or can behave like a write operation and output results to a user-specified collection.
@example Create the map/reduce operation.
MapReduce.new({ :selector => { :mapreduce => 'test_coll', :map => '', :reduce => '' }, :db_name => 'test_db' })
Initialization:
param [ Hash ] spec The specifications for the operation. option spec :selector [ Hash ] The map reduce selector. option spec :db_name [ String ] The name of the database on which the operation should be executed. option spec :options [ Hash ] Options for the map reduce command.
@since 2.0.0