我可以用以下方法解决这个问题：

DO 
BEGIN
    DECLARE arr1 TINYINT ARRAY = ARRAY(1,2,3,4);
    DECLARE arr2 INTEGER ARRAY = ARRAY(1,2);

--convert array in table rst1 with column name col1
    rst1 = UNNEST(:arr1) as (COL1);
--convert array in table rst2 with column name col1 
    rst2 = UNNEST(:arr2) as (COL1);
--query with minus
    select  col1 from :rst1  
              minus
    select col1 from :rst2;
END;