I just noticed that HistoryService.deleteHistoricProcessInstance() does not delete the sub processes which were executed during the process, this is a different behavior than runtimeService.deleteProcessInstance(). Is this intended or should I report a bug report?
If this is not a bug, how do I read all historic sub process? I could not find any API like RuntimeService.createProcessInstanceQuery().superProcessInstanceId().
As I looked at the Database I can't find the super process value in "act_hi_procinst" table, there is a field "super_exec_" in the "act_ru_execution" table. But this value seems to get lost as soon as a process is completed.