Question

select current_timestamp(6),    current_timestamp(0)
----------------------------------------------------
2012-02-22 16:03:45.988418+13 | 2012-02-22 16:03:46+13
           -------^                   ------------^ (date from the future)

This query can easily return the timestamp from the future for the second column because of current_timestamp(0) is rounding “mathematically”. This could lead to some unexpected errors, just because the retrieved time is from the future up to 0.5s.

So my question is – what is the simplest way to round current_timestamp(6) to the nearest second down?

PS: I know the solution with converting to seconds and back

PPS: The result should be a timestamp type, not a string

UPD:

Found a solution

select current_timestamp(6), current_timestamp(0)::abstime

Answer 1

select current_timestamp(6),    date_trunc('second', current_timestamp(6))