Re: [PATCH] Initial progress reporting for COPY command

On Sun, Jun 21, 2020 at 01:40:34PM +0200, Josef Šimánek wrote:
>Thanks for all comments. I have updated code to support more options
>(including STDIN/STDOUT) and added some documentation.
>
>Patch is attached and can be found also at
>https://github.com/simi/postgres/pull/5.
>
>Diff version: https://github.com/simi/postgres/pull/5.diff
>Patch version: https://github.com/simi/postgres/pull/5.patch
>
>I'm also attaching screenshot of HTML documentation and html documentation
>file.
>
>I'll do my best to get this to commitfest now.
>

I see we're not showing the total number of bytes the COPY is expected
to process, which makes it hard to estimate how far we actually are.
Clearly there are cases when we really don't know that (exports, import
from stdin/program), but why not to show file size for imports from a
file? I'd expect that to be the most common case.

I wonder if it made sense to show some estimates in the other cases. For
example when exporting query result, maybe we could show the estimated
number of rows and size? Of course, that's prone to estimation errors
and it's more a wild idea for the future, I don't expect this patch to
implement that.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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