Re: Fix for Extra Parenthesis in pgbench progress message

Hi,

On 2025-02-07 12:58:38 -0500, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
> > I just did pgbench -i 100 -q via ssh and noticed it was *way* slower than I
> > expected. Did it with debian's pgbench, no such issue.
>
> > It's due to this patch.
>
> Oh! The problem is that the hunk
>
> + /*
> + * If the previous progress message is longer than the current one,
> + * add spaces to the current line to fully overwrite any remaining
> + * characters from the previous message.
> + */
> + if (prev_chars > chars)
> + fprintf(stderr, "%*c", prev_chars - chars, ' ');
> + fputc(eol, stderr);
> + prev_chars = chars;
>
> is executed unconditionally for each data row, when we should only run
> it when we printed something.

Yea, that would do it.

> Trying it here, it also makes the thing practically unresponsive to
> control-C.

Interestingly I don't see that aspect...

> > Given the upcoming set of minor releases, I think it may be best for this this
> > patch ought to be reverted for now.
>
> Seems easy enough to fix. But it's now middle of the night Saturday
> morning in Japan, so I doubt Masao-san or Ishii-san will see this
> for awhile. And the release freeze is coming up fast.
>
> Let me have a go at fixing it, and if it turns out to be harder
> than I think, I'll revert it instead.

Makes sense!

Greetings,

Andres Freund