Re: BUG #17606: There is still some glitch in 3f7323cbb fixing failure of MULTIEXPR_SUBLINK

 

If I consider it correctly, can we fix the initplan SubPlan issue simply
as below?

--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -911,6 +911,13 @@ SS_make_multiexprs_unique(PlannerInfo *root, PlannerInfo *subroot)
                new_multiexpr_params = lappend(new_multiexpr_params, params);
        }

+       /*
+        * It's OK for initplan SubPlans to share output parameters, so we do not
+        * need to generate new Param nodes for them.
+        */
+       if (new_multiexpr_params == NIL)
+               return;
+
        /*
         * Now we must find the Param nodes that reference the MULTIEXPR outputs
         * and update their sublink IDs so they'll reference the new outputs.

Thanks
Richard