Re: Re: Used size of a datafile.

hi,Jesper Haure Norrevang

 OS file is one oracle blocks bigger than oracle files .

 2k/4k/8k/16k blocks LMT datafile has 8 oracle blocks oracle file header and bitmap . there is difference for dba_extents and (dba_data_files - dba_free_space) and please notice the left space with a datafile that less than min extent.

anyway,i think all that is not important.

Best regards

msn: biti_rainy_at_hotmail.com
a dba from alibaba(china)

• from the mail-----
  >Thanks Jared,
  >
  >I think you have a good point here.
  >I don't like when ad hoc SQL made by
  >the DBA shows up as the most resource
  >consuming statements in the database.
  >I admit that my statement do not perform
  >well.
  >
  >It reminds me, that the sum of bytes
  >in DBA_FREE_SPACE and DBA_EXTENTS for
  >a tablespace do not match the actual
  >size of the datafiles. The difference is:
  >- 1 block file header,
  >- 1 block HEADER of bitmap used with locally
  > managed tablespaces (LMT).
  >- 6 blocks (may be more?) of LMT-bitmaps.
  >
  >The difference can be seen in
  >DBA_DATA_FILES as the difference between
  >USER_BYTES and BYTES.
  >
  >Regards
  >Jesper Haure Norrevang
  >
  >
  >----- Original Message -----
  >From: Jared Still <jkstill_at_gmail.com>
  >Date: Saturday, January 8, 2005 8:09 pm
  >Subject: Re: Used size of a datafile.
  >
  >> You may consider using DBA_FREE_SPACE rather than DBA_EXTENTS.
  >>
  >> If there are a lot of objects in your database, it may be
  >> (possibly much) less
  >> expensive to query DBA_FREE_SPACE.
  >>
  >> On Sat, 08 Jan 2005 11:15:32 +0100, Jesper Haure Norrevang
  >> <jhn.aida_at_cbs.dk> wrote:
  >> > Vinod,
  >> >
  >> > select
  >> > f.tablespace_name,
  >> > f.file_name,
  >> > sum(e.bytes) / 1024 / 1024 MB
  >> > from dba_extents e, dba_data_files f
  >> > where e.file_id = f.file_id
  >> > group by f.tablespace_name, f.file_name
  >> > order by f.tablespace_name, f.file_name;
  >> >
  >>
  >>
  >> --
  >> Jared Still
  >> Certifiable Oracle DBA and Part Time Perl Evangelist
  >> --
  >> http://www.freelists.org/webpage/oracle-l
  >>
  >
  >--
  >http://www.freelists.org/webpage/oracle-l
  >
  

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