Hi Huanbing,
Thank you for your interest and insightful question about the TraversalState
concept. You've identified exactly the right challenge with the custom
executor approach.
However, as Ashutosh suggested, let's keep this thread focused on the
current PGQ patch. Your question about DFS backtracking and PlanState
management deserves a thorough discussion, which we can have once the
current work is committed.
I'm looking forward to discussing VLE implementation details with you
and the community then.
Best regards,
Henson