Re: Fractions of seconds in timestamps

From: Vincenzo Romano <vincenzo(dot)romano(at)notorand(dot)it>
To: Jasen Betts <jasen(at)xnet(dot)co(dot)nz>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Fractions of seconds in timestamps
Date: 2012-04-25 09:43:50
Message-ID: CAHjZ2x64jotU6+oiNXfhyFwr-s=ZisOfkGDDxOF3QcA7ZNKGUg@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

2012/4/25 Jasen Betts <jasen(at)xnet(dot)co(dot)nz>:
> On 2012-04-25, Valentin Militaru <valentin(dot)militaru(at)telcor(dot)ro> wrote:
>> This is a multi-part message in MIME format.
>> --------------050404030901030607030308
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>> Content-Transfer-Encoding: 7bit
>>
>> What about using
>>
>> WHERE f BETWEEN '2012-04-23 00:00:00' AND '2012-04-24 00:00:00'?
>>
>
> that could match the first microsecond of 2012-04-24
> otherwise not a prolem :)
>
> another option is BETWEEN '2012-04-23 00:00:00' AND '2012-04-23 23:59:60'
>
> or even BETWEEN '2012-04-23 00:00:00' AND '2012-04-23 23:59:60.999999'
>
> these are reliant on documented behaviours, but documented
> inosyncratic behaviours, behaviours that could potentially be improved.
> such that it woulkd no longer be reliable.
>
>>> you have to do it the long way
>>>
>>>     f>= '2012-04-23 00:00:00' AND f<  '2012-04-24 00:00:00'
>>>
>
> this way is mathematically correct and relies on standard guaranteed
> behaviours only.
>
> --
> ⚂⚃ 100% natural

Correct Jasen!
In my opinion the use of BETWEEN (as it is currently defined) makes
very little sense (if any) at least for time stamps.
What I've seen so far with time periods are always defined as either
"[...)" or "(..]".

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Ken Tanzer 2012-04-25 10:57:06 PHP SQL Color Syntax that is Postgresql & GPL3 Compatible?
Previous Message Toby Corkindale 2012-04-25 09:42:39 Re: Bug? Query plans / EXPLAIN using gigabytes of memory