Re: Fix for Extra Parenthesis in pgbench progress message

Hi,

On 2025-02-07 12:58:38 -0500, Tom Lane wrote:
> Andres Freund <andres@anarazel.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