Hvorfor får jeg Ora-30004, når sys_connect_by_path afgrænser ikke er til stede i kolonneværdier

Det lugter af en bug. Hvis du har brug for at omgå det og implementere din logik, kan du alternativt bruge rekursiv subquery factoring (rekursiv With), som fungerer ok i 11.2.0.4:

SQL> with t (id, label, parentid, reportlevel, fake_connect_by_path) as (
  2  select id, label, parentid, 0 as reportlevel, ' -> ' || label as fake_connect_by_path
  3    from temptable
  4   where parentid is null
  5   union all
  6  select tt.id, tt.label, tt.parentid, reportlevel + 1, t.fake_connect_by_path || ' -> ' || tt.label as fake_connect_by_path
  7    from temptable tt
  8    join t on t.id = tt.parentid
  9  )
 10  select fake_connect_by_path
 11    from t;
FAKE_CONNECT_BY_PATH
--------------------------------------------------------------------------------
 -> ninechars
 -> Im stumped
 -> - Unknown -
 -> ninechars -> erewrettt