def old_items(mtime=(Time.now.to_i)-(172800))
      data = db.execute <<SQL
        SELECT * from artifacts where modified < #{mtime}
SQL
      data || []
    end
def old_items(mtime=(Time.now.to_i)-(172800))
      data = db.execute <<SQL
        SELECT * from artifacts where modified < #{mtime}
SQL
      data || []
    end
get items older than mtime, defaults to 2 days ago