Re: Why we are going to have to go DirectIO

Jeff Janes <jeff.janes@gmail.com> writes:
> On Tue, Dec 3, 2013 at 11:39 PM, Claudio Freire <klaussfreire@gmail.com>wrote:
>> Problem is, Postgres relies on a working kernel cache for checkpoints.
>> Checkpoint logic would have to be heavily reworked to account for an
>> impaired kernel cache.

> I don't think it would need anything more than a sorted checkpoint.

Nonsense.  We don't have access to the physical-disk-layout information
needed to do reasonable sorting; to say nothing of doing something
intelligent in a multi-spindle environment, or whenever any other I/O
is going on concurrently.
        regards, tom lane