Re: Streaming base backups

On Wed, Jan 5, 2011 at 23:58, Dimitri Fontaine <dimitri@2ndquadrant.fr> wrote:
>> * Stefan mentiond it might be useful to put some
>> posix_fadvise(POSIX_FADV_DONTNEED)
>>   in the process that streams all the files out. Seems useful, as long as that
>>   doesn't kick them out of the cache *completely*, for other backends as well.
>>   Do we know if that is the case?
>
> Maybe have a look at pgfincore to only tag DONTNEED for blocks that are
> not already in SHM?

It's not much of an improvement. For pages that we already have in
shared memory, OS cache is mostly useless. OS cache matters for pages
that *aren't* in shared memory.

Regards,
Marti