On 04/14/2015 05:32 PM, Tom Lane wrote:
> Heikki Linnakangas <hlinnaka@iki.fi> writes:
>> On 04/14/2015 02:24 AM, Tom Lane wrote:
>>> Wait a minute. Didn't you just break PITR scenarios? The *entire point*
>>> of the multiple-timeline mechanism is that you can start a new WAL history
>>> from a point in the past without destroying WAL history after that point
>>> on the old timeline.
>
>> It deletes the files belonging to other timelines from pg_xlog only. The
>> WAL archive is not touched.
>
> How do we know those files are in the WAL archive?
Presumably that's where they came from if you're doing PITR. Or they
were copied into pg_xlog manually from somewhere else.
After PITR, if you decide that you didn't like the result and perform
another recovery, you have to restore from a base backup again, which
will wipe out pg_xlog anyway.
Also, if the recovery continued longer, those files would be deleted
from pg_xlog anyway, at a later restartpoint.
- Heikki