Re: Windows now has fdatasync()

Great. File sync is a Nice extension for me, as I don't know all file
structures.

Thomas Munro <thomas.munro@gmail.com> schrieb am So., 12. Dez. 2021, 03:48:

> Hi,
>
> While porting some new IO code to lots of OSes I noticed in passing
> that there is now a way to do synchronous fdatasync() on Windows.
> This mechanism doesn't have an async variant, which is what I was
> actually looking for (which turns out to doable with bleeding edge
> IoRings, more on that later), but I figured this might be useful
> anyway.  I see that at least one other open source database has
> discovered it and seen speedups.  Like some other file API
> improvements discussed recently, it's Windows 10+ and NTFS only.  I
> tried out a quick POC patch and it runs a bit faster than fsync(), as
> expected.  I'm not sure if it's worth bothering with or not given the
> other options, but figured it was worth sharing.
>
> While testing that I also couldn't resist adding an extra output line
> to pg_test_fsync to run open_datasync in buffered I/O mode, like
> PostgreSQL actually does in real life.  I guess I should really change
> it to duplicate less code, though...
>
> [1]
> https://www.postgresql.org/message-id/flat/1527846213.2475.31.camel%40cybertec.at
>