Improve comments for trivial_subqueryscan(). This function can be called from mark_async_capable_plan(), a helper function for create_append_plan(), before set_subqueryscan_references(), to determine the triviality of a SubqueryScan that is a child of an Append plan node, which is done before doing finalize_plan() on the SubqueryScan (if necessary) and set_plan_references() on the subplan, unlike when called from set_subqueryscan_references(). The reason why this is safe wouldn't be that obvious, so add comments explaining this.
Follow-up for commit c2bb02bc2. Reviewed by Zhihong Yu. Discussion: https://postgr.es/m/CAPmGK17%2BGiJBthC6va7%2B9n6t75e-M1N0U18YB2G1B%2BE5OdrNTA%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/4a8a5dd7f59cd8dd9969cef1969cb5f7c5124eec Modified Files -------------- src/backend/optimizer/plan/setrefs.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
