Re: Time-Delayed Standbys

On 12 December 2013 15:03, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Dec 12, 2013 at 9:52 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Simon Riggs <simon@2ndQuadrant.com> writes:
>>> On 12 December 2013 11:05, Andres Freund <andres@2ndquadrant.com> wrote:
>>>>> My suggestion would be to add the TZ to the checkpoint record. This
>>>>> way all users of WAL can see the TZ of the master and act accordingly.
>>>>> I'll do a separate patch for that.
>>
>>>> Intuitively I'd say that might be useful - but I am not reall sure what
>>>> for. And we don't exactly have a great interface for looking at a
>>>> checkpoint's data. Maybe add it to the control file instead?
>>
>>> That's actually what I had in mind, I just phrased it badly in mid-thought.
>>
>> I don't think you realize what a can of worms that would be.  There's
>> no compact representation of "a timezone", unless you are only proposing
>> to store the UTC offset; and frankly I'm not particularly seeing the point
>> of that.
>
> +1.  I can see the point of storing a timestamp in each checkpoint
> record, if we don't already, but time zones should be completely
> irrelevant to this feature.  Everything should be reckoned in seconds
> since the epoch.

Don't panic guys! I meant UTC offset only. And yes, it may not be
needed, will check.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services