code: def get_last_block(self, cur=None):
          
          sql = 'SELECT MAX(block_height) FROM {};'.format(self.subdomain_table)
          cursor = None
          if cur is None:
              cursor = self.conn.cursor()
          else:
              cursor = cur
  
          rows = db_query_execute(cursor, sql, ())
          height = 0
          try:
              rowdata = rows.fetchone()
              height = rowdata['MAX(block_height)']
          except:
              height = 0
  
          return height
docs: Get the highest block last processed