Re: Switch pg_basebackup to use -X stream instead of -X fetch by default?

On Wed, Aug 27, 2014 at 5:16 AM, Fujii Masao <masao.fujii@gmail.com> wrote:
> On Wed, Aug 27, 2014 at 6:16 AM, Magnus Hagander <magnus@hagander.net> wrote:
>> On Tue, Aug 26, 2014 at 10:46 PM, Andres Freund <andres@2ndquadrant.com> wrote:
>>> On 2014-08-26 16:41:44 -0400, Peter Eisentraut wrote:
>>>> On 8/26/14 12:40 PM, Magnus Hagander wrote:
>>>> > I think the first reason is gone now, and the risk/damage of the two
>>>> > connections is probably smaller than running out of WAL. -x is a good
>>>> > default for smaller systems, but -X is a safer one for bigger ones. So
>>>> > I agree that changing the default mode would make sense.
>>>>
>>>> I would seriously consider just removing one of the modes.  Having two
>>>> modes is complex enough, and then having different defaults in different
>>>> versions, and fuzzy recommendations like, it's better for "smaller
>>>> systems", it's quite confusing.
>>>
>>> Happy with removing the option and just accepting -X for backward
>>> compat.
>>
>> Works for me - this is really the cleaner way of doing it...
>
> We cannot use -X stream with tar output format mode. So I'm afraid that
> removing -X fetch would make people using tar output format feel disappointed.
> Or we should make -X stream work with tar mode.

Ah, yes, I've actually had that on my TODO for some time.

I think the easy way of doing that is to just create an xlog.tar file.
Since we already create "base.tar" and possibly n*<tablespace.tar>,
adding one more file shouldn't be a big problem, and would make such
an implementation much easier. Would be trivial to do .tar.gz for it
as well, just like for the others.

-- Magnus HaganderMe: http://www.hagander.net/Work: http://www.redpill-linpro.com/