From: webtourist on
solution found:

SELECT deptno,
substr(REPLACE(REPLACE(xmlagg(xmlelement("x", job) ORDER BY
job), '</x>'), '<x>', ' '), 2) job_list,
wmsys.wm_concat(DISTINCT job) job_list_distinct
FROM emp
GROUP BY deptno
ORDER BY deptno



I win :)