这个XML文件的xpath是什么？

Question

<root>
 <level OPERATORE="maria bianca_amadeo" QUARTIERE="Quartiere 1 - Ricerca 
 oggetti - Versione a" LEVEL="1" DATA="2016-04-18 17:59">
  <track X="-237" Y="0" Z="155" TEMPO="0" />
  <track X="-237" Y="0" Z="155" TEMPO="2" />
  <track X="-238" Y="0" Z="155" TEMPO="4" />
  <track X="-249" Y="0" Z="161" TEMPO="6" />
  <track X="-260" Y="0" Z="167" TEMPO="8" />

CREATE TABLE public.james AS
SELECT (xpath('//root/level/track', x))[1]::text AS id
FROM   unnest(xpath('/root/level/track', myxml)) x;
RETURN TRUE;

如何选择包含X，Y，Z和T​​empo的行？ 结果将给出所有行。