Re: calling procedures is slow and consumes extra much memory against calling function

On Sun, May 10, 2020 at 10:20:53PM +0200, Pavel Stehule wrote:
> When I rewrite same to functions then
>
> create or replace function p1func2(inout r int, inout v int) as $$
> begin v := random() * r; end
> $$ language plpgsql;
>
> Then execution is about 1 sec, and memory requirements are +/- zero.
>
> Minimally it looks so CALL statements has a memory issue.

Behavior not limited to plpgsql. A plain SQL function shows the same
leak patterns:
create or replace procedure p1_sql(in r int, in v int)
as $$ SELECT r + v; $$ language sql;
And I cannot get valgrind to complain about lost references, so this
looks like some missing memory context handling.

Also, I actually don't quite get why the context created by
CreateExprContext() cannot be freed before the procedure returns. A
short test shows no problems in calling FreeExprContext() at the end
of ExecuteCallStmt(), but that does not address everything. Perhaps a
lack of tests with pass-by-reference expressions and procedures?

Peter?
--
Michael