Re: Very slow queries followed by checkpointer process killed with signal 9

Jason McLaurin <jason(at)jcore(dot)io> writes:
> Is there anywhere you'd suggest we start looking for hints? I'd be
> interested in increasing relevant logging verbosity so that we can see when
> key background processes are running, both in Postgres core and Timescale.

It might be helpful to try to identify which wait events the slow
queries are blocking on (pg_stat_activity.wait_event_type and
.wait_event). I'm not sure if you're going to be able to extract
useful data, because your query on pg_stat_activity is likely to
be slow too. But it's a place to start.

Also, given that you're evidently incurring the wrath of the OOM
killer, you should try to understand why the kernel thinks it's
under memory pressure. Do you have too many processes, or perhaps
you've configured too much shared memory?

regards, tom lane