Re: GUC with units, details

Martijn van Oosterhout wrote:
> >
> > How about this:
> >
> > INFO: Your setting was converted to IEC standard binary
> units. Use KiB,
> > MiB, and GiB to avoid this warning.
>
> That's silly. If you're going to treat KB as 1024 bytes anyway,
> complaining about it is just being pedantic.

But after a version or two with warnings, we have grounds to make it an
error. I'd rather just go with the standard from day 1 and reject
decimal units where they don't make sense, but that seems unlikely.

>
> The thing is, most memory sizes in postgres need to be some
> multiple of
> a page size. You can't have a shared buffers of exactly 100000 bytes,
> while 102400 bytes is possible. When someone has a GB of memory, they
> really mean a GiB, but no-one bothers to correct them.

And hard drives are just the opposite: a 250GB drive does not have
268,435,456,000 bytes of unformatted space.

>
> Is there anywhere in postgres where using K=1000 would be
> significantly
> clearer than K=1024?

If the unit for a setting is pages, then a value of '1K' could cause
some confusion as to whether that's 1,000 or 1,024 pages.

>
> Have a nice day,
> --
> Martijn van Oosterhout <kleptog(at)svana(dot)org>
> http://svana.org/kleptog/
> > From each according to his ability. To each according to
> his ability to litigate.
>