> > Another thing I am wondering about is why we're not using fdatasync(),
> > where available, instead of fsync(). The whole point of preallocating
> > the WAL files is to make fdatasync safe, no?
>
> This still looks like it'd be a win, by reducing the number of seeks
> needed to complete a WAL logfile flush. Right now, each XLogFlush
> requires writing both the file's data area and its inode.
Don't we have to fsync the inode too? Actually, I was hoping sequential
fsync's could sit on the WAL disk track, but I can imagine it has to
seek around to hit both areas.
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026
