Re: calling procedures is slow and consumes extra much memory against calling function

st 10. 6. 2020 v 12:26 odesílatel Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com>
napsal:

> On Sat, 16 May 2020 at 00:07, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
> wrote:
> >
> > Hi
> >
> >>>
> >>> The problem is in plpgsql implementation of CALL statement
> >>>
> >>> In non atomic case - case of using procedures from DO block, the
> expression plan is not cached, and plan is generating any time. This is
> reason why it is slow.
> >>>
> >>> Unfortunately, generated plans are not released until SPI_finish.
> Attached patch fixed this issue.
> >>
> >>
> >> But now, recursive calling doesn't work :-(. So this patch is not enough
> >
> >
> > Attached patch is working - all tests passed
>
> Could you show an example testcase that tests this recursive scenario,
> with which your earlier patch fails the test, and this v2 patch passes
> it ? I am trying to understand the recursive scenario and the re-use
> of expr->plan.
>

it hangs on plpgsql tests. So you can apply first version of patch

and "make check"

> >
> > It doesn't solve performance, and doesn't solve all memory problems, but
> significantly reduce memory requirements from 5007 bytes to 439 bytes per
> one CALL
>
> So now this patch's intention is to reduce memory consumption, and it
> doesn't target slowness improvement, right ?
>

yes. There is a problem with planning every execution when the procedure
was called from not top context.

> --
> Thanks,
> -Amit Khandekar
> Huawei Technologies
>