Just added 64k to that datafile and an additional 100m magically appeared in
dba_free_space. Don't know where I picked up the idea that you could only
add that 64k at file creation time but it's obviously wrong. Thanks for the
help Jonathan.
"Chuck" <chuckh_nospam_at_softhome.net> wrote in message
news:ab8jfu$fd3bc$1_at_ID-85580.news.dfncis.de...
> I thought you could only add that 64k on datafile creation, otherwise the
> entire 100m extent was used for the bitmap instead of just 64k.
>
> "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
> news:1020719801.27156.0.nnrp-07.9e984b29_at_news.demon.co.uk...
> >
> > I'll guess that your uniform extent size is 100MB, and
> > your file size is 1700 MB.
> >
> > If so, add 64K to the file size and you'll find that your
> > dba_free_space jumps by 100MB.
> >
> > dba_free_space measures usable free space, and if
> > you don't allow 64K at the head of the file for the bitmap
> > header on an LMT, then there will be a gap at the end of
> > the file which is too small for a complete extent, and
> > therefore doesn't appear as free space.
> >
> > --
> > Jonathan Lewis
> > http://www.jlcomp.demon.co.uk
> >
> > Author of:
> > Practical Oracle 8i: Building Efficient Databases
> >
> > Next Seminar - Australia - July/August
> > http://www.jlcomp.demon.co.uk/seminar.html
> >
> > Host to The Co-Operative Oracle Users' FAQ
> > http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> >
> >
> >
> > Chuck wrote in message ...
> > >Can someone tell me what's going on here? I always thought that the
size
> of
> > >the allocated extents plus the free space in a datafile would equal the
> > >total size of the datafile. That doesn't appear to be true with this
> file.
> > I
> > >think dba_free_space or dba_extents is missing something. BTW this
> datafile
> > >is the sole datafile of a locally managed tablespace.
> > >
> > >select 'free space' block_class,sum(bytes)/1048576 megabytes
> > >from dba_free_space where file_id = 733
> > >union all
> > >select 'used extents',sum(bytes)/1048576 megabytes
> > >from dba_extents where file_id = 733
> > >union all
> > >select 'total in file',sum(bytes)/1048576 megabytes
> > >from dba_data_files where file_id = 733;
> > >
> > >Here's the results. They don't add up.
> > >
> > >BLOCK_CLASS MEGABYTES
> > >------------- ----------
> > >free space 200
> > >used extents 1400
> > >total in file 1700
> > >
> > >Platform: SGI IRIX64
> > >Oracle version: 8.1.7.2.0 (the current 8i patch for IRIX).
> > >
> > >
> >
> >
>
>
Received on Tue May 07 2002 - 08:43:43 CDT
