WITH RECURSIVE temp1 ( p_id,p_parent,p_title,PATH, LEVEL, NAME  ) AS (
    SELECT T1.p_id,T1.p_parent, T1.p_title, CAST (T1.p_id AS VARCHAR (50)) as PATH, 1 , CAST (T1.p_title AS VARCHAR (255)) as NAME
        FROM "SC_Wonder".t_page T1 WHERE T1.p_parent IS NULL
    union
    select T2.p_id, T2.p_parent, T2.p_title, CAST ( temp1.PATH ||'->'|| T2.p_id AS VARCHAR(50)) ,LEVEL + 1 ,
    CAST (  '   '|| temp1.NAME AS VARCHAR(255))
         FROM "SC_Wonder".t_page T2 INNER JOIN temp1 ON( temp1.p_id= T2.p_parent))
    select * from temp1 ORDER BY PATH LIMIT 100

CAST (  lpad('', (LEVEL + 1)*3, ' ') || T2.p_title AS VARCHAR(255))