Re: Something for the TODO list: deprecating abstime and friends

From: Mark Dilger <hornschnorter(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Something for the TODO list: deprecating abstime and friends
Date: 2017-07-19 05:44:02
Message-ID: AD2781E2-928C-497C-9FF2-FE629605F1C4@gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers


> On Jul 18, 2017, at 9:13 PM, Mark Dilger <hornschnorter(at)gmail(dot)com> wrote:
>
>>
>> On Jul 17, 2017, at 2:34 PM, Mark Dilger <hornschnorter(at)gmail(dot)com> wrote:
>>
>>>
>>> On Jul 17, 2017, at 2:14 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>
>>> Mark Dilger <hornschnorter(at)gmail(dot)com> writes:
>>>>> On Jul 17, 2017, at 12:54 PM, Mark Dilger <hornschnorter(at)gmail(dot)com> wrote:
>>>> On Jul 15, 2017, at 3:00 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>>>> The types abstime, reltime, and tinterval need to go away, or be
>>>>>> reimplemented, sometime well before 2038 when they will overflow.
>>>
>>>>> These types provide a 4-byte datatype for storing real-world second
>>>>> precision timestamps, as occur in many log files. Forcing people to
>>>>> switch to timestamp or timestamptz will incur a 4 byte per row
>>>>> penalty. In my own builds, I have changed the epoch on these so
>>>>> they won't wrap until sometime after 2100 C.E. I see little point in
>>>>> switching to an 8-byte millisecond precision datatype when a perfectly
>>>>> good 4-byte second precision datatype already serves the purpose.
>>>
>>> Well, if you or somebody is willing to do the legwork, I'd be on board
>>> with a plan that says that every 68 years we redefine the origin of
>>> abstime. I imagine it could be done so that currently-stored abstime
>>> values retain their present meaning as long as they're not too old.
>>> For example the initial change would toss abstimes before 1970 overboard,
>>> repurposing that range of values as being 2038-2106, but values between
>>> 1970 and 2038 still mean the same as they do today. If anybody still
>>> cares in circa 2085, we toss 1970-2038 overboard and move the origin
>>> again, lather rinse repeat.
>>>
>>> But we're already past the point where it would be time to make the
>>> first such switch, if we're gonna do it. So I'd like to see somebody
>>> step up to the plate sooner not later.
>>
>> Assuming other members of the community would not object to such
>> a plan, I'd be willing to step up to that plate. I'll wait a respectable time,
>> maybe until tomorrow, to allow others to speak up.
>
> There was not much conversation about this, so I went ahead with what
> I think makes a logical first step. The attached patch removes the tinterval
> datatype from the sources.
>
> I intend to remove reltime next, and then make the changes to abstime in
> a third patch.

As predicted, this second patch (which should be applied *after* the prior
tinterval_abatement patch) removes the reltime datatype from the sources.

mark

Attachment Content-Type Size
reltime_abatement.patch.1 application/octet-stream 52.6 KB

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Haribabu Kommi 2017-07-19 06:03:20 Re: Pluggable storage
Previous Message Fabien COELHO 2017-07-19 05:41:27 Re: merge psql ef/ev sf/sv handling functions