Re: Improvements and additions to COPY progress reporting

On Fri, Feb 19, 2021 at 2:34 AM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
> > On Mon, 15 Feb 2021 at 17:07, Tomas Vondra
> > <tomas.vondra@enterprisedb.com> wrote:
> >>
> >> - The blocks in copyfrom.cc/copyto.c should be reworked - I don't think
> >> we do this in our codebase.
> >
> > I saw this being used in (re)index progress reporting, that's where I
> > took inspiration from. It has been fixed in the attached version.
> >
>
> Hmmm, good point. I haven't looked at the other places reporting
> progress and I only ever saw this pattern in old code. I kinda dislike
> these blocks, but admittedly that's rather subjective view. So if other
> similar places do this when reporting progress, this probably should
> too. What's your opinion on this?

Actually in the code base the style of that variable declaration and
usage of pgstat_progress_update_multi_param is a mix. For instance, in
lazy_scan_heap, ReindexRelationConcurrently, the variables are
declared at the start of the function. And in _bt_spools_heapscan,
index_build, validate_index, perform_base_backup, the variables are
declared within a separate block.

IMO, we can have the arrays declared at the start of the functions
i.e. the way it's done in v8-0001, because we can extend them for
reporting some other parameter(maybe in future).

> >> - I fir the "io_target" name misleading, because in some cases it's
> >> actually the *source*.
> >
> > Yes, I was also not quite happy with this, but couldn't find a better
> > one at the point of writing the initial patchset. Would
> > "io_operations", "io_port", "operates_through" or "through" maybe be
> > better?
> >
>
> No idea. Let's see if someone has a better proposal ...

 For COPY TO the name "source_type" column and for COPY FROM the name
"destination_type" makes sense. To have a combined column name for
both, how about naming that column as "io_type"?

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com