Re: Clarify: default precision on timestamps is 6

On Fri, Oct 13, 2023 at 7:32 AM David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Friday, October 13, 2023, PG Doc comments form <noreply(at)postgresql(dot)org>
> wrote:
>
>> both of them round any precision
>> beyond microseconds, and neither returns timestamps with greater precision
>> than the value that was inserted.
>>
>
> That is precisely what a no default with maximum of six means. If we say
> the default is six that would imply storage of less precise values pads
> significant zeros until there are six.
>
> David J.
>
>
Not sure that last statement is correct. In 13 (only system I have access
to at the moment) it doesn't look like casting to a precision greater than
the value originally had causes any padding:

some_system=# select CURRENT_TIMESTAMP(0)::timestamp(6) with time zone;
current_timestamp
------------------------
2023-10-13 17:19:00+00
(1 row)

some_system=# select CURRENT_TIMESTAMP(1)::timestamp(6) with time zone;
current_timestamp
--------------------------
2023-10-13 17:23:04.2+00
(1 row)