def clear(self, match="*", count=1000):
        """ :see:meth:RedisMap.clear """
        cursor = '0'
        pipe = self._client.pipeline(transaction=False)
        while cursor != 0:
            cursor, keys = self.scan(cursor=cursor, match=match, count=count)
            if keys:
                pipe.delete(*keys)
        pipe.hdel(self._bucket_key, self.key_prefix)
        pipe.execute()
        return True