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 - 08:06:02 CDT
