Re: 8.4 open item: copy performance regression?

Tom Lane wrote:
> Just eyeing the code ... another thing we changed since 8.3 is to enable
> posix_fadvise() calls for WAL.  Any of the complaints want to try diking
> out this bit of code (near line 2580 in src/backend/access/transam/xlog.c)?
> 
> #if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
>     if (!XLogArchivingActive() &&
>         (get_sync_bit(sync_method) & PG_O_DIRECT) == 0)
>         (void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED);
> #endif

doesn't seem to cause any noticable difference for me...


Stefan