Re: RFC: Logging plan of the running query

On 25/06/2026 11:43, Robert Haas wrote:
> On Wed, Jun 24, 2026 at 10:35 AM Andrei Lepikhov <lepihov(at)gmail(dot)com> wrote:
>> 1. pg_log_query_plan - This function just sends a signal. There are no
>> guarantees that actual action will be performed. So, the 'request' word makes
>> more sense for me.
>
> I don't agree with this particular comment. Of course nothing is
> absolutely guaranteed because the database system could crash or the
> world could end, but if the target backend is running a query, it
> should log the query plan. Therefore, I don't see the need for a word
> like "request".
>

Ok, so just mention this behaviour in the documentation - let people know that
they should potentially wait for a minute or two more to see the EXPLAIN.
Real-life with huge queries and big machines provide us with examples where a
backend might delay a response to a signal for quite a substantial time.

Sometimes nothing happens after such an async operation, and we need to identify
the problem: has the backend stalled, is the ‘logging plan’ algorithm
ineffective, or is something else happening?

--
regards, Andrei Lepikhov,
pgEdge