Re: your mail

From: Jared Still <jared_at_SIERRA.VALLEYNET.COM>
Date: Tue, 16 Jan 1996 06:25:04 -0800
Message-Id: <9601161455.AA12399@alice.jcc.com>

>
> > Is it possible to approximately estimate how much disk space a export of the
> > full oracle database will occupy.
> >
> > Thanks
> >
> > Sriram
> >
> > Email : krishnan_at_panasun.panasonicfa.com
> >
>
> Dear Sriram,
>
> You select the datafiles from the database by the following
> way.Then you add the size of this data files.
>
> SQL>select name,bytes from v$datafile
> where status = 'ONLINE';
>
> In this way you can get size of the full database.
>
> Regards.
> Rajib Agarwala
> raj123_at_hclggn.hcla.com
>

Data files are merely the containers for data. The data in your tables may only use 10% of the available space, so the size of your datafiles may be 100 meg, but your export only 10 meg.

Use this query from sqlplus to determine your free space:

   break on report
   compute sum of meg on report
   select

      tablespace_name tbs,
      (bytes/1048576) MEG

   from dba_free_space
   order by tbs,meg desc

Now determine the full size of the database:

   select

      file_name,
      (bytes/1048576) MEG

   from dba_data_files
   order by file_name, meg desc

Subtract the freespace total from the datafile total and this should be a good approximation of your database size for export purposes.

you could also use 'analyze' on each table and index, and get a more accurate size, but this would take ( a lot ) longer.

Jared

jared_at_valleynet.com Received on Tue Jan 16 1996 - 09:56:07 CST