Re: Avoiding inadvertent debugging mode for pgbench

On Thu, Feb 29, 2024 at 07:05:13PM -0500, Greg Sabino Mullane wrote:
> Attached please find a patch to adjust the behavior of the pgbench program
> and make it behave like the other programs that connect to a database
> (namely, psql and pg_dump). Specifically, add support for using -d and
> --dbname to specify the name of the database. This means that -d can no
> longer be used to turn on debugging mode, and the long option --debug must
> be used instead.
>
> This removes a long-standing footgun, in which people assume that the -d
> option behaves the same as other programs. Indeed, because it takes no
> arguments, and because the first non-option argument is the database name,
> it still appears to work. However, people then wonder why pgbench is so
> darn verbose all the time! :)
>
> This is a breaking change, but fixing it this way seems to have the least
> total impact, as the number of people using the debug mode of pgbench is
> likely quite small. Further, those already using the long option are
> unaffected, and those using the short one simply need to replace '-d' with
> '--debug', arguably making their scripts a little more self-documenting in
> the process.

I think this is a generally reasonable proposal, except I don't know
whether this breakage is acceptable. AFAICT there are two fundamental
behavior changes folks would observe:

* "-d <database_name>" would cease to emit the debugging output, and while
enabling debug mode might've been unintentional in most cases, it might
actually have been intentional in others.

* "-d" with no argument or with a following option would begin failing, and
users would need to replace "-d" with "--debug".

Neither of these seems particularly severe to me, especially for a
benchmarking program, but I'd be curious to hear what others think.

--
Nathan Bossart
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