Re: "Deallocate Unused" not releasing space above HWM

  • From: "Ron Rogers" <RROGERS@xxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 10 Mar 2004 10:05:51 -0500

Mladen,
 You are 100% correct in you statement about reclaiming the unused
space. I would also suggest that the data be exported before the
truncation followed by an import   or  you can practice the recovery
policy that you have established.
Ron

>>> mladen@xxxxxxxxxxxxxxx 03/10/2004 9:35:15 AM >>>
On 03/10/2004 07:27:43 AM, vidya kalyanaraman wrote:
> Hi All
>  I am trying to reclaim the wasted space (huge deletes), which are
above 
> the HWM.  I had analysed the table before and got the "empty_blocks"

> details from dba_tables.
> I am using the following query,
>  alter table tab1 deallocate unused;
> and then to bring down the HWM,
> alter table tab1 move tablespace AR_DATA;  ---- Moved within the same

> tablespace
> and then I had rebuilt all the corresponding indexes.
> As a last step, I had coalesced the tablespace.
> Next day (because SMON is not going to clear it up immediately), I
had 
> analyzed the tables again and got the "empty_blocks" details from 
> dba_tables.

Strictly speaking "deallocate unused" is not supposed to change the
HWM. Truncate is.
Truncate your tables and HWM will be moved back. Way back.
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com 
----------------------------------------------------------------
To unsubscribe send email to:  oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at //www.freelists.org/archives/oracle-l/
FAQ is at //www.freelists.org/help/fom-serve/cache/1.html 
-----------------------------------------------------------------
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to:  oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at //www.freelists.org/archives/oracle-l/
FAQ is at //www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------

Other related posts: