Re: v16dev: invalid memory alloc request size 8488348128

[Justin Pryzby]

On Sat, Apr 15, 2023 at 11:33:58AM +1200, David Rowley wrote:
> On Sat, 15 Apr 2023 at 10:48, Justin Pryzby <pry...@telsasoft.com> wrote:
> >
> > On Sat, Apr 15, 2023 at 10:04:52AM +1200, David Rowley wrote:
> > > Which aggregate function is being called here?  Is it a custom
> > > aggregate written in C, by any chance?
> >
> > That function is not an aggregate:
> 
> There's an aggregate somewhere as indicated by this fragment from the
> stack trace:
> 
> > #12 project_aggregates (aggstate=aggstate@entry=0x607200070d38) at 
> > ../src/backend/executor/nodeAgg.c:1377
> > #13 0x0000000000903eb6 in agg_retrieve_direct 
> > (aggstate=aggstate@entry=0x607200070d38) at 
> > ../src/backend/executor/nodeAgg.c:2520
> > #14 0x0000000000904074 in ExecAgg (pstate=0x607200070d38) at 
> > ../src/backend/executor/nodeAgg.c:2172
> 
> Any chance you could try and come up with a minimal reproducer?  You
> have access to see which aggregates are being used here and what data
> types are being given to them and then what's being done with the
> return value of that aggregate that's causing the crash.  Maybe you
> can still get the crash if you mock up some data to aggregate and
> strip out the guts from the plpgsql functions that we're crashing on?

Try this

CREATE OR REPLACE FUNCTION avfinal(x anycompatiblearray) RETURNS 
anycompatiblearray
LANGUAGE plpgsql AS $$
DECLARE
    res real[];
BEGIN
    res := ARRAY_FILL(x[1], ARRAY[4]);
    RETURN res;
END;
$$;

CREATE OR REPLACE FUNCTION acc(x anycompatiblearray, y anycompatiblearray) 
RETURNS anycompatiblearray
LANGUAGE plpgsql AS $$
BEGIN
    RETURN ARRAY_FILL(y[1], ARRAY[4]);
END;
$$;

CREATE OR REPLACE AGGREGATE public.av(anycompatiblearray) (
    STYPE = anycompatiblearray,
    INITCOND = '{{0},{0}}',
    SFUNC = acc,
    FINALFUNC = avfinal
);

CREATE OR REPLACE FUNCTION aw(real[])
RETURNS void LANGUAGE plpgsql
AS $function$
    begin
    end
$function$;

SELECT 
aw(av(ARRAY[1.0::real])),
aw(av(ARRAY[1.0::real])),
1;