On Thu, Jan 25, 2018 at 09:30:45AM -0500, Robert Haas wrote:
> On Wed, Jan 24, 2018 at 10:31 PM, Tsunakawa, Takayuki
> <tsunakawa.takay@jp.fujitsu.com> wrote:
>>> This is just a guess, of course. You didn't mention what the underlying
>>> storage for your test was?
>>
>> Uh, your guess was correct. My file system was ext3, where fsync() writes all dirty buffers in page cache.
>
> Oh, ext3 is terrible. I don't think you can do any meaningful
> benchmark results on ext3. Use ext4 or, if you prefer, xfs.
Or to put it short, the lack of granular syncs in ext3 kills
performance for some workloads. Tomas Vondra's presentation on such
matters are a really cool read by the way:
https://www.slideshare.net/fuzzycz/postgresql-on-ext4-xfs-btrfs-and-zfs
(I would have loved seeing this presentation in live).
--
Michael