Re: Temp Tablespace Group, Adding Tempfile and Resumable Transaction Issue?
Date: Thu, 7 Jan 2010 06:56:50 +1100
This is a good tip - thanks. What about if you're using ASM (e.g. for RAC)?
On Thu, Jan 7, 2010 at 6:48 AM, Tanel Poder <tanel_at_poderc.com> wrote:
> Yeah, temp tablespace files are created as sparse files. If you use ls -ls
> on Unix you'll see the real amount of OS blocks used by the file as the
> first column of the output.
> Sparse files cause problems - one thing is that DBAs see from df that
> there's lots of free space on a mountpoint - and place new datafiles there.
> Now if a sparse file actually starts using its space, it may end up with out
> of space and resulting IO errors.
> Also, IIRC, sparse files disable direct IO and cause fallback to buffered IO
> in some cases.
> So, a good practice for creating temp files is to use "mkfile" command in OS
> first to create the files which really reserve the disk space for themselves
> and then "create temp tablespace tempfile 'xyz' REUSE"
> Tanel Poder
> http://blog.tanelpoder.com (just switched to new blog template!)