# File lib/rubyrep/session.rb, line 42
    def manual_primary_keys(db_arm)
      manual_primary_keys = {}
      resolver = TableSpecResolver.new self
      table_pairs = resolver.resolve configuration.included_table_specs, [], false
      table_pairs.each do |table_pair|
        options = configuration.options_for_table(table_pair[:left])
        key_names = options[:key]
        if key_names == nil and options[:auto_key_limit] > 0
          if left.primary_key_names(table_pair[:left], :raw => true).empty?
            column_names = left.column_names(table_pair[:left])
            if column_names.size <= options[:auto_key_limit]
              key_names = column_names
            end
          end
        end
        if key_names
          table_name = table_pair[db_arm]
          manual_primary_keys[table_name] = [key_names].flatten
        end
      end
      manual_primary_keys
    end