Database Design Advice

[James Laver]

On Fri, Nov 8, 2013 at 5:22 PM, Yitzchak Scott-Thoennes
<sthoenna at gmail.com> wrote:
> On Fri, Nov 8, 2013 at 12:38 AM, Mark Stringer <mark at repixl.com> wrote:
>> I'd guess that the date_created is being stored in the table, so could be
>> used to order the records without the need for a serial, if ordering is the
>> only concern.
>
> Never use date/times as unique identifiers/sort keys.

I'll agree with the former, but what's the reasoning behind the latter?

James