Re: [HACKERS] Decimal64 and Decimal128

On Sun, Jun 18, 2017 at 2:31 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Sat, Jun 17, 2017 at 3:50 PM, Thomas Munro
> <thomas.munro@enterprisedb.com> wrote:
>> On Sun, Jun 18, 2017 at 5:38 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>>> I feel like these would logically just be different types, like int4
>>> and int8 are.  We don't have integer(9) and integer(18).
>>
>> Hmm.  Perhaps format_type.c could render decfloat16 as decfloat(16)
>> and decfloat34 as decfloat(34), and gram.y could have a production
>> that selects the right one when you write DECFLOAT(x) and rejects
>> values of x other than 16 and 34.
>
> What would be the point of that?

We'd accept and display the new SQL:2016 standard type name with
length, but by mapping it onto different internal types we could use a
pass-by-value type when it fits in a Datum.

-- 
Thomas Munro
http://www.enterprisedb.com