Segmentation fault when running min_n max_n on big data set

[oddfrost]

Relevant system information:

• OS: alma linux 8.7
• PostgreSQL version: 14.7
• TimescaleDB Toolkit version: 1.16.0
• Installation method: timescaledb repo, self hosted package

Describe the bug
Postgres crashes when executing query like
select
min_n(metric, 2)
from table;

Data set (1 000 000+ rows)
In postgres log i can see message: server process was terminated by signal 11: Segmentation fault.

To Reproduce
Steps to reproduce the behavior:
CREATE TABLE public.test("time" timestamptz NOT NULL, duration int4 NULL);

SELECT create_hypertable('test', 'time');

Do $$
Begin
For r in 1..1000000 loop
Insert into test values(now() + (r||'s')::interval, r);
end loop;
End;
$$;

Select min_n(duration, 2) from test;

Expected behavior
Get result with smallest numbers (1, 2)

Actual behavior
Process crushes with segmentation fault (but it works on small data sets, with four rows).

[oddfrost]

May be related to

#755

[jerryxwu]

@oddfrost thank you for reporting the issue. I have reproduced the issue that you've experienced. We'll consider fixing it in an upcoming release.

[jerryxwu]

@oddfrost If you haven't noticed yet, the fix has been included in the latest 1.17.0 release.