Hi HuiSheng,
[...] The most easiest way to store the start of a process is extending the JBPM4_EXECUTION, we could add a starter column, or something like this.
[...]
I read the related forum posts and the JIRA about this, maybe i still miss the point here, but extending the JBPM4_EXECUTION table for this seems wrong to me. A much better approach imho would be to keep that information in a swimlane like it is done in JBPM3 ( see: http://docs.jboss.org/jbpm/v3/userguide/taskmanagement.html section 11.7)
...and thanks for your great work on jBPM4