Re: Use pg_pwritev_with_retry() instead of write() in dir_open_for_write() to avoid partial writes? - Mailing list pgsql-hackers

On Wed, Sep 28, 2022 at 12:32 AM Thomas Munro <thomas.munro@gmail.com> wrote:
>
> On Wed, Sep 28, 2022 at 1:03 AM Bharath Rupireddy
> <bharath.rupireddyforpostgres@gmail.com> wrote:>
> > On Tue, Sep 27, 2022 at 3:01 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> > > Something like the attached.
> >
> > Isn't it also better to add notes in win32pread.c and win32pwrite.c
> > about the callers doing lseek(SEEK_SET) if they wish to and Windows
> > implementations changing file position? We can also add a TODO item
> > about replacing pg_ versions with pread and friends someday when
> > Windows fixes the issue? Having it in the commit and include/port.h is
> > good, but the comments in win32pread.c and win32pwrite.c make life
> > easier IMO. Otherwise, the patch LGTM.
>
> Thanks, will do.

I'm looking forward to getting it in.

> FWIW I doubt the OS itself will change released
> behaviour like that, but I did complain about the straight-up
> misleading documentation and they agreed and fixed it[1].
>
> [1] https://github.com/MicrosoftDocs/sdk-api/pull/1309

Great! Is there any plan to request for change in WriteFile() to not
alter file position?

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com