Re: RFC: Logging plan of the running query

út 27. 7. 2021 v 20:34 odesílatel Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com>
napsal:

>
>
> On 2021/07/09 14:05, torikoshia wrote:
> > On 2021-07-02 23:21, Bharath Rupireddy wrote:
> >> On Tue, Jun 22, 2021 at 8:00 AM torikoshia <torikoshia(at)oss(dot)nttdata(dot)com>
> wrote:
> >>> Updated the patch.
> >>
> >> Thanks for the patch. Here are some comments on the v4 patch:
> >
> > Thanks for your comments and suggestions!
> > I agree with you and updated the patch.
> >
> > On Thu, Jul 1, 2021 at 3:34 PM Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com>
> wrote:
> >
> >> DO $$
> >> BEGIN
> >> PERFORM pg_sleep(100);
> >> END$$;
> >>
> >> When I called pg_log_current_query_plan() to send the signal to
> >> the backend executing the above query, I got the following log message.
> >> I think that this is not expected message. I guess this issue happened
> >> because the information about query text and plan is retrieved
> >> from ActivePortal. If this understanding is right, ISTM that we should
> >> implement new mechanism so that we can retrieve those information
> >> even while nested query is being executed.
> >
> > I'm now working on this comment.
>
> One idea is to define new global pointer, e.g., "QueryDesc
> *ActiveQueryDesc;".
> This global pointer is set to queryDesc in ExecutorRun()
> (also maybe ExecutorStart()). And this is reset to NULL in ExecutorEnd()
> and
> when an error is thrown. Then ProcessLogCurrentPlanInterrupt() can
> get the plan of the currently running query from that global pointer
> instead of ActivePortal, and log it. Thought?
>

It cannot work - there can be a lot of nested queries, and at the end you
cannot reset to null, but you should return back pointer to outer query.

Regards

Pavel

> Regards,
>
> --
> Fujii Masao
> Advanced Computing Technology Center
> Research and Development Headquarters
> NTT DATA CORPORATION
>
>
>