Re: Add timeline to partial WAL segments

On 12/11/18 11:14 PM, Robert Haas wrote:
> On Wed, Dec 12, 2018 at 1:13 PM David Steele <david(at)pgmasters(dot)net> wrote:
>> On 12/11/18 11:06 PM, Robert Haas wrote:
>>> On Wed, Dec 12, 2018 at 11:29 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>>>> I really don't think that it is a good idea to link a future timeline
>>>> within a segment which includes in its name a direct reference to its
>>>> current timeline. Also I don't buy much the argument that those
>>>> segments are a nuisance as well all the time. They may be for some
>>>> tools, however not for others depending on the archiving strategy
>>>> (distributed locations for example), and if they are a problem for your
>>>> deployments, why not just discarding them within the archive command and
>>>> be done with them?
>>>
>>> -1. Writing an archive_command already requires a PhD in
>>> PostgreSQL-ology. The very last thing we should do is invent even
>>> more ways for an archive command to be subtly wrong.
>>
>> The point here is to make archive commands simpler. As it is, the
>> various backup tools are going to need to find ways to deal with the
>> problem, and each solution will be different.
>>
>> The goal is to come up with a solution that works and that all archive
>> commands can use, rather than each one rolling their own solution.
>
> I understand. I'm more or less agreeing with you. Actually, I'm not
> really sure whether your particular proposal is the best way of
> handling this, but I disagree with Michael's suggestion that we should
> just throw responsibility back on archive_command.

I apologize, I misread that. Your comments make a lot more sense now
that I read them in the correct context!

And yeah, I'm not sure that I'm totally sold on this idea either, but I
wanted to get a conversation going.

--
-David
david(at)pgmasters(dot)net