Re: truncating timestamps on arbitrary intervals

On Sat, Apr 10, 2021 at 7:43 AM Peter Eisentraut <
peter(dot)eisentraut(at)enterprisedb(dot)com> wrote:
>
> On 30.03.21 18:06, John Naylor wrote:
> > Currently, when the origin is after the input, the result is the
> > timestamp at the end of the bin, rather than the beginning as expected.
> > The attached puts the result consistently at the beginning of the bin.
>
> In the patch
>
> + if (origin > timestamp && stride_usecs > 1)
> + tm_delta -= stride_usecs;
>
> is the condition stride_usecs > 1 really necessary? My assessment is
> that it's not, in which case it would be better to omit it.

Without the condition, the case of 1 microsecond will fail to be a no-op.
This case has no practical use, but it still must work correctly, just as
date_trunc('microsecond', input) does.

--
John Naylor
EDB: http://www.enterprisedb.com