Re: Infinities in type numeric - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Infinities in type numeric
Date
Msg-id CA+Tgmoa2pAO7WyqspRstWMw4cFqYZ8KFWgWRjgDFdNJrb64tMw@mail.gmail.com
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In response to Re: Infinities in type numeric  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Infinities in type numeric  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
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



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