Re: [PATCH] Cleanup of GUC units code - Mailing list pgsql-hackers

On Wed, 03 Sep 2008 18:32:16 +0300
Hannu Krosing <hannu@krosing.net> wrote:

> > We have had this discussion before, I even submitted a patch to
> > make them case insensitive. In retrospect I was wrong to submit
> > that patch. SQL may be case insensitive but units are not. MB !=
> > Mb != mb , 
> 
> For most people they are equal, and all mean MEGABYTE(S) though
> http://en.wikipedia.org/wiki/MB has lots of other possible meanings
> for each.

O.k. there is an interesting point being made here, "For most people".

Which people exactly? Are we talking about the general populous? If so
I would argue that "most people" don't have a clue what MB, Mb, or mb
is except to say I think that means some kind of speed or capacity.

The above is not our target.

If our definition of most people is, "those who are reasonably
technically adept and will be deploying PostgreSQL in production on
some level".

If someone doesn't know the difference between Mb and MB on a
production system, I would not want them anywhere near any instance of
a production system.

If we are going to make sweeping statements (anyone on this thread)
about user-hostile and most people, then we better define what those
mean. This whole argument about making something easier (and incorrect)
for someone who doesn't exist and has not been defined.

I would be hung on this list if I made a similar argument about any
other feature.

> 
> > I don't think we should encourage in any way for users to do the
> > wrong thing.
> 
> Can you see any scenario where accepting case insensitive units does
> more damage than just ignoring the conf line with "incorrect" casing ?

Generally speaking, no I can't think of any damage that could be done
from mixed casing. Especially since we would only accept certain
possibilities, e.g; Mb would equal MB.

It just strikes me as really bad that a project that prides itself on
"doing it right" is willing to make this type of sacrifice. This isn't
about usability. This is about doing it wrong and actively encouraging
our users that "wrong is ok". It could also misinform the user about
what the meaning of the value means.

> 
> Or do you mean we should discourage people from editing
> postgresql.conf manually and have them use some tool which prevents
> them entering "kb" ?

Well that is a whole other argument :P. I would be happy to have that
one on another thread.

Sincerely,

Joshua D. Drake

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