On Fri, Jun 1, 2018 at 3:13 PM, Laurenz Albe <laurenz.a...@cybertec.at> wrote:
> I recently read our documentation about reliability on Windows: > > > On Windows, if wal_sync_method is open_datasync (the default), write > caching can > > be disabled by unchecking > > My Computer\Open\disk drive\Properties\Hardware\Properties\Policies\Enable > write caching > > on the disk. Alternatively, set wal_sync_method to fsync or > fsync_writethrough, > > which prevent write caching. > > It seems dangerous to me to initialize "wal_sync_method" to a method that > is unsafe > by default. Admittedly I am not a Windows man, but the fact that this has > eluded me > up to now leads me to believe that other people running PostgreSQL on > Windows might > also have missed that important piece of advice and are consequently > running with > an unsafe setup. > > Wouldn't it be smarter to set a different default value on Windows, like > we do on > Linux (for other reasons)? > > One thing to note is that it seems that in code we use FILE_FLAG_WRITE_THROUGH for open_datasync which according to MSDN [1] will bypass any intermediate cache . See pgwin32_open. Have you experimented to set any other option as we have a comment in code which say Win32 only has O_DSYNC? [1] - https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
