# File lib/mongo/db.rb, line 455
    def drop_index(collection_name, index_name)
      oh = BSON::OrderedHash.new
      oh[:deleteIndexes] = collection_name
      oh[:index] = index_name.to_s
      doc = command(oh, :check_response => false)
      ok?(doc) || raise(MongoDBError, "Error with drop_index command: #{doc.inspect}")
    end