On Wed, Dec 9, 2015 at 4:41 PM, Andres Freund <andres@anarazel.de> wrote:
> On 2015-12-09 16:30:47 +0900, Michael Paquier wrote:
>> > I'm kinda wondering if it wouldn't have been better to go through shared
>> > buffers in ResetUnloggedRelationsInDbspaceDir() instead of using
>> > copy_file().
>>
>> For deployment with large shared_buffers settings, wouldn't that be
>> actually more costly than the current way of doing? We would need to
>> go through all the buffers at least once and look for the INIT_FORKNUM
>> present to flush them.
>
> We could just check the file sizes on disk, and the check for the
> contents of all the pages for each file.
By doing it at replay, the flushes are spread across time. And by
doing it at the end of recovery, all the flushes would be grouped. Do
you think that's fine?
--
Michael