text: -- @testpoint: pg_partition_size(text, text)指定名称的分区使用的磁盘空间。其中，第一个text为表名，第二个text为分区名。
  
  create table test (id int8)
  with(orientation = column)
  partition by range (id)
  (
          partition "P1" values less than (1000),
          partition "P2" values less than (2000)
  );
  
  INSERT INTO test VALUES(999);
  INSERT INTO test VALUES(888);
  INSERT INTO test VALUES(1999);
  
  SELECT pg_partition_size('test','P1');
  SELECT pg_partition_size('test','P2');
  
  drop table test;