Re: archive_command during database shutdown

On 25/05/16 20:57, Jeff Janes wrote:
> On Wed, May 25, 2016 at 10:31 AM, Sameer Kumar  wrote:
>>
>>
>> On Thu, 26 May 2016, 1:25 a.m. Jeff Janes,  wrote:
>>>
>>> I've recently wanted to run a different archive_command during
>>> database shutdown than during normal operations.  In particular, if
>>> the normal archive process fails during normal operations, I want it
>>> to be retried later (as it currently does).  But if it fails during
>>> shutdown, I want it to run a fallback archive_command.
>>
>>
>> What version of PostgreSQL are you using?
>
> 9.2, 9.4, 9.5, 9.6beta.
>
>>
>>>
>>> The only way I can see to accomplish this is to have the
>>> archive_command try to connect back to the database and see if it gets
>>> an error.  That seems pretty ugly.  Is there a better way?
>>
>>
>> What's your goal here?
>
> I want my database to shut down cleanly when I tell it to.
>
>>
>> During a shutdown, if you don't so much care about checkpoint and fsync of
>> buffers to disk, you can do an immediate shutdown.
>
> But I do care about the checkpoint.  Otherwise you lose all your
> unlogged tables.  And probably other unfortunate things happen, as

Isn't that the point of unlogged tables? Or rather, isn't that the risk 
you knowingly take with them - you trade reliability for speed?

Ray