less is more

app/models/dunlop/source_file_model.rb

@@ -181,15 +181,16 @@ module Dunlop::SourceFileModel
     def latest_processed
       if base_class == self
         join_select = processed.select('MAX(id) AS max_id').group(:sti_type)
+        #join_select = processed.selecting{ id.maximum.as('max_id')}.group(:sti_type)
         joins("INNER JOIN (#{join_select.to_sql}) tmp ON id = tmp.max_id")
       else # return the latest process of the specific source-file class
         # 2 query based solution, probably faster than the one (sub) query solution
-        processed.find_by(id: processed.maximum(:id))
+        find_by(id: processed.maximum(:id))
 
         ## ONE QUERY SOLUTIONS
-        #   processed.find_by(id: processed.select('MAX(id)'))
+        #   find_by(id: processed.select('MAX(id)'))
         # OR using baby squeel
-        #   processed.find_by(id: processed.selecting{ id.maximum })
+        #   find_by(id: processed.selecting{ id.maximum })
       end
     end