instance method hash_rows

# File activerecord/lib/active_record/result.rb, line 105
    def hash_rows
      @hash_rows ||=
        begin
          # We freeze the strings to prevent them getting duped when
          # used as keys in ActiveRecord::Base's @attributes hash
          columns = @columns.map { |c| c.dup.freeze }
          @rows.map { |row|
            # In the past we used Hash[columns.zip(row)]
            #  though elegant, the verbose way is much more efficient
            #  both time and memory wise cause it avoids a big array allocation
            #  this method is called a lot and needs to be micro optimised
            hash = {}

            index = 0
            length = columns.length

            while index < length
              hash[columns[index]] = row[index]
              index += 1
            end

            hash
          }
        end
    end