Re: [COMMITTERS] pgsql: Speed up CREATE DATABASE by deferring the fsyncs until after

On Monday 15 February 2010 12:34:44 marcin mank wrote:
> On Mon, Feb 15, 2010 at 11:02 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Hi Marcin,
> >
> > Sounds rather unlikely to me. Its likely handled at an upper layer (vfs
> > in linux' case) and only overloaded when an optimized implementation is
> > available. Which os do you see implementing that only on a part of the
> > filesystems?
>
> I have a Windows XP dev machine, which runs virtualbox, which runs
> ubuntu, which mounts a windows directory through vboxfs

> btw: 8.4.2 initdb won`t work there too, So this is not a regression.
> The error is:
> DEBUG: creating and filling new WAL file
> LOG: could not link file "pg_xlog/xlogtemp.2367" to
> "pg_xlog/000000010000000000000000" (initialization of log file 0,
> segment 0): Operation not permitted
> FATAL: could not open file "pg_xlog/000000010000000000000000" (log
> file 0, segment 0): No such file or directory
That does seem to be a different issue. Currently there are no fsyncs on
directories at all, so likely your setup is hosed anyway ;-)

> But I would not be that sure that eg. NFS or something like that won`t
> complain.
It does not.

> Ignoring the return code seems the right choice.
And the error hiding one as well. With delayed allocation you theoretically
could error out on fsync with -ENOSPC ...

Andres