>>> Brad Nicholson <bnichols@ca.afilias.info> wrote:
> On Fri, 2008-10-31 at 17:38 +0200, Peter Eisentraut wrote:
>> Tom Lane wrote:
>> > Why is this worth spending effort on?
>>
>> The addition of archive_mode changeable with restart only was a
>> significant loss of usability going from 8.2 to 8.3, in the minds of
>> many people.
>
> I put my hand up as one of those people.
Now that I better understand the issue, I don't think there was any
loss of functionality. There was one change that broke compatibility
(possibly unnecessarily) and one enhancement which you may or may not
be able to use, depending on your work-flow.
The compatibility change was that if you want to turn off WAL file
archiving without restarting the database, you now have to set your
archive_command to 'exit 1' or '/bin/true' (or similar) instead of
setting it to an empty string.
The new feature is that if you don't want to archive WAL files without
a restart, you can use the archive_mode setting and get the benefit of
several optimizations. If you need to toggle, you get to choose
between restarts to enable the optimizations, or legacy techniques to
keep the database running.
Seems reasonable enough to me.
We might have an opportunity to expand the documentation here....
-Kevin