On Fri, Jun 12, 2020 at 2:14 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
> > BTW, has there been any thought to supporting a negative scale for the
> > numeric data type? If you can cut off digits after the decimal, why
> > not before?
>
> Hm, would there be any real use-case?
Compatibility... apparently people do use it.
> An implementation issue is that even in the "long" numeric format,
> we cram dscale into a 14-bit unsigned field. You could redefine
> the field as signed and pray that nobody has dscales above 8K
> stored on disk, but I'm dubious that there's a good argument for
> taking that risk.
That doesn't sound too appealing I guess, but couldn't you enforce it
as a typemod without changing the on-disk representation of the
values?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company