Re: Add proper planner support for ORDER BY / DISTINCT aggregates

 

According to this comment in primnodes.h, the planner is not supposed to
treat implicit and explicit casts differently.  In this case
set_plan_references is doing its job correctly, to adjust both random()
FuncExprs in targetlist to refer to subplan's output for query 2.  As a
consequence we would get a sorted output.

I'm still confused that when the same scenario happens with ORDER BY in
an aggregate function, like in query 1, the result is different in that
we would get an unsorted output.

I wonder if we should avoid this inconsistent behavior.

Thanks
Richard