Re: Memory leak on subquery as scalar operand

On Tue, 1 Nov 2022 at 17:10, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Maybe the different "inlining" choice makes a difference?

The single subquery version also crashes for me, so perhaps it's just
the amount of memory that's being used and when the OOM killer is
triggering.

It crashes even when I set jit_inline_above_cost and
jit_optimize_above_cost above the query's cost.

postgres=# set jit_optimize_above_cost=10000000;
SET
postgres=# set jit_inline_above_cost=10000000;
SET
postgres=# set jit=0;
SET
postgres=# explain verbose SELECT
id,
(SELECT count(*) FROM leak_test y WHERE y.id=l.id) as y_result
FROM leak_test l;
QUERY PLAN
------------------------------------------------------------------------------------------------------------
Seq Scan on public.leak_test l (cost=0.00..941723.86 rows=112965 width=12)
Output: l.id, (SubPlan 1)
SubPlan 1
-> Aggregate (cost=8.31..8.32 rows=1 width=8)
Output: count(*)
-> Index Only Scan using leak_test_pkey on
public.leak_test y (cost=0.29..8.31 rows=1 width=0)
Output: y.id
Index Cond: (y.id = l.id)
(8 rows)

postgres=# set jit=1;
SET
postgres=# explain verbose SELECT
id,
(SELECT count(*) FROM leak_test y WHERE y.id=l.id) as y_result
FROM leak_test l;
server closed the connection unexpectedly

David