Re: timestamps, formatting, and internals

On 05/29/2012 04:28 PM, David Salisbury wrote:
>
>
> On 5/27/12 12:25 AM, Jasen Betts wrote:
>> The query: "show integer_datetimes;" should return 'on' which means
>> timestamps are microsecond precision if it returns 'off' your database
>> was built with floating point timstamps and equality tests will be
>> unreliable,
>
> I find that rather interesting. I was told that I was losing microseconds
> when I extracted an epoch from the difference between two timestamps and
> casted
> that value to an integer. So if I have integer timestamps ( your case
> above )
> I get microseconds, but integer epochs is without microseconds?

test=> SELECT extract(epoch from(now() - (now() - interval '1.345577 sec')));
date_part
-----------
1.345577

test=> SELECT extract(epoch from(now() - (now() - interval '1.345577 sec')))::int;
date_part
-----------
1

An integer is an integer so you will lose all the fractional parts:)

>
> Thanks,
>
> -ds
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com