Re: query_id, pg_stat_activity, extended query protocol

On 15/5/2024 12:09, Michael Paquier wrote:
> On Wed, May 15, 2024 at 03:24:05AM +0000, Imseih (AWS), Sami wrote:
>>> I think we should generally report it when the backend executes a job
>>> related to the query with that queryId. This means it would reset the
>>> queryId at the end of the query execution.
>>
>> When the query completes execution and the session goes into a state
>> other than "active", both the query text and the queryId should be of the
>> last executed statement. This is the documented behavior, and I believe
>> it's the correct behavior.
>>
>> If we reset queryId at the end of execution, this behavior breaks. Right?
>
> Idle sessions keep track of the last query string run, hence being
> consistent in pg_stat_activity and report its query ID is user
> friendly. Resetting it while keeping the string is less consistent.
> It's been this way for years, so I'd rather let it be this way.
Okay, that's what I precisely wanted to understand: queryId doesn't have
semantics to show the job that consumes resources right now—it is mostly
about convenience to know that the backend processes nothing except
(probably) this query.

--
regards, Andrei Lepikhov