Re: [PATCH] Initial progress reporting for COPY command

po 15. 6. 2020 v 2:18 odesílatel Michael Paquier <michael(at)paquier(dot)xyz>
napsal:

> Hi Josef,
>
> On Sun, Jun 14, 2020 at 02:32:33PM +0200, Josef Šimánek wrote:
> > Hello, as proposed by Pavel Stěhule and discussed on local czech
> PostgreSQL
> > maillist (
> >
> https://groups.google.com/d/msgid/postgresql-cz/CAFj8pRCZ42CBCa1bPHr7htffSV%2BNAcgcHHG0dVqOog4bsu2LFw%40mail.gmail.com?utm_medium=email&utm_source=footer
> ),
> > I have prepared an initial patch for COPY command progress reporting.
>
> Sounds like a good idea to me.
>
> > I have not found any tests for progress reporting. Are there any? It
> would
> > need two backends running (one running COPY, one checking output of
> report
> > view). Is there any similar test I can inspire at? In theory, it should
> be
> > possible to use dblink_send_query to run async COPY command in the
> > background.
>
> We don't have any tests in core. I think that making deterministic
> test cases is rather tricky here as long as we don't have a more
> advanced testing framework that allows is to lock certain code paths
> and keep around an expected state until a second session comes around
> and looks at the progress catalog (even that would need adding more
> code to core to mark the extra point looked at). So I think that it is
> fine to not focus on that for this feature. The important parts are
> the choice of the progress points and the data sent to MyProc, and
> both should be chosen wisely.
>
> > My initial (attached) patch also doesn't introduce documentation for this
> > system view. I can add that later once this patch is finalized (if that
> > happens).
>
> You may want to add it to the next commit fest:
> https://commitfest.postgresql.org/28/
> Documentation is necessary, and having some would ease reviews.
>

I have added documentation, more code comments and I'll upload patch to
commit fest.

> --
> Michael
>