text: -- @testpoint: opengauss比较操作符<=，参数互换结果互斥
  -- 运算的交换性
  select 'students'::text <= 'student'::text;
  select 'student'::text <= 'student'::text;
  select '521'::money <= '520'::money;
  select '520'::money <= '521'::money;
  select 't'::BOOLEAN <= 'f'::BOOLEAN;
  select 'f'::BOOLEAN <= 't'::BOOLEAN;