Re: Renaming of pg_xlog and pg_clog

On 29 August 2016 at 20:28, Michael Paquier <michael.paquier@gmail.com> wrote:
> On Mon, Aug 29, 2016 at 5:28 PM, Craig Ringer
> <craig.ringer@2ndquadrant.com> wrote:
>> On 29 August 2016 at 14:30, Michael Paquier <michael.paquier@gmail.com> wrote:
>>> On Mon, Aug 29, 2016 at 2:36 PM, Craig Ringer
>>> <craig.ringer@2ndquadrant.com> wrote:
>>>> I don't care if it comes as part of some greater reorg or not but I'll be
>>>> really annoyed if scope creep lands up killing the original proposal to just
>>>> rename these dirs. I think that a simple rename should be done first. Then
>>>> if some greater reorg is to be done it can be done shortly after. The only
>>>> people that'll upset are folks tracking early 10.0 dev and they'll be aware
>>>> it's coming.
>>>
>>> Okay, so let's do it. Attached are two patches:
>>> - 0001 renames pg_clog to pg_trans. I have let clog.c with its current
>>> name, as well as its structures. That's the mechanical patch, the ony
>>> interesting part being in pg_upgrade.
>>> - 0002 renames pg_xlog to pg_wal.
>>
>> Is there any expectation that a 10.0 pg_basebackup should work on a
>> 9.x server, or fail to work gracefully? There doesn't look to be any
>> version specific handling of the rename there.
>
> Oops. Per the docs:
> pg_basebackup works with servers of the same or an older major
> version, down to 9.1. However, WAL streaming mode (-X stream) only
> works with server version 9.3 and later, and tar format mode
> (--format=tar) of the current version only works with server version
> 9.5 or later.
>
> So we need to do a bit better than what the patch proposes, but that's
> actually just tweaking the things with pg_xlog/pg_wal depending on the
> version of the target server.

Cool. I'll mark as waiting on author pending that.

It'll be good to get this footgun put away.

-- Craig Ringer                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Remote DBA, Training
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