ALTER TABLE table_name ADD [IF NOT EXISTS]
  PARTITION (partition_spec)
  [PARTITION (partition_spec) ...]

partition_spec:
  : partition_column = partition_col_value, partition_column = partition_col_value, ...


ALTER TABLE tbl ADD PARTITION (p1=1, p2='a');

ALTER TABLE tbl ADD IF NOT EXISTS PARTITION (P1 = 1) PARTITION (P2 = 2);