Re: RFC: Logging plan of the running query

On 28/9/2023 09:04, torikoshia wrote:
> On 2023-09-25 18:49, Andrey Lepikhov wrote:
>> On 25/9/2023 14:21, torikoshia wrote:
>>> On 2023-09-20 14:39, Lepikhov Andrei wrote:
>>> Hmm, as a test, I made sure to call ProcessLogQueryPlanInterrupt() on
>>> all CFI using
>>> v28-0002-Testing-attempt-logging-plan-on-ever-CFI-call.patch, and
>>> then ran the following query but did not cause any problems.
>>>
>>> ```
>>> =# CREATE TABLE test();
>>> =# CREATE OR REPLACE FUNCTION ddl() RETURNS void AS $$
>>> BEGIN
>>>    EXECUTE format('ALTER TABLE test ADD COLUMN x integer;');
>>>    PERFORM pg_sleep(5);
>>> END; $$ LANGUAGE plpgsql VOLATILE;
>>> =# SELECT ddl();
>>> ```
>>>
>>> Is this the case you're worrying about?
>>
>> I didn't find a problem either. I just feel uncomfortable if, at the
>> moment of interruption, we have a descriptor of another query than the
>> query have been executing and holding resources.
>
> I think that "descriptor" here refers to ActiveQueryDesc, in which case
> it is updated at the beginning of ExecutorRun(), so I am wondering if
> the situation you're worried about would not occur.
As you can see, in my example we have the only DDL and no queries with
plans. In this case postgres doesn't call ExecutorRun() just because it
doesn't have a plan. But locks will be obtained.

--
regards,
Andrey Lepikhov
Postgres Professional