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Re: Online "tablespace" reorg ?

From: Bob <>
Date: Tue, 28 Jun 2005 23:43:14 -0400
Message-ID: <>

A little more information of my environment . These are all DSS - Oracle on HPUX 11.1... Database sizes are from 5 - 20TB The largest table space approx 800GB containing approx 20-50 segments, tablespaces average about 200GB +-

90% are DMT & no ASSM

We are concerned with reclaiming space and switching to LMT and ASSM. Im thinking of creating new tablespaces with these attributes find the dependent segments and alter table move... and recreate the indexes.

I suspect CTAS involves more TEMP space and therefor slower, where I believe move creates a copy of the table and then drops the old and that can be done online (off peak)

as far as online table reorg, there is dbms_redefinition which allows modifying columns etc...

Just wondering others opinions of

1- reclaiming space with such large objects 2 - opinions on using ASSM
3 - recommendations from others who have "been there" :)


Allen, Brandon wrote:
> Hi Bob,
> No, I don't believe there is anyway to do an online table reorg, much less an online tablespace reorg. There is an ONLINE option for the ALTER TABLE . . MOVE statement, but unfortunately it is for use with IOTs only.
> I think your only options are to use the ALTER TABLE . . . MOVE like you've already mentioned, or to use exp/imp, with a drop/create of the tablespaces in the middle to recreate the tablespaces as LMT w/ ASSM.
> Regards,
> Brandon
> -----Original Message-----
> From:
> []On Behalf Of Bob
> Sent: Tuesday, June 28, 2005 2:54 PM
> To:
> Subject: Online "tablespace" reorg ?
> All-
> Is there such a thing as online tablespace reorg?
> All, I've been tasked to perform an "online reorg of our tablespaces"
> From my research I come to these findings.
> 1 - tablespace reorg is not a popular topic and only seems to be available
> using oem which due to our diverse environment, I need to use a
> sqlplus script. From reading ask tom he is claiming there really isn't
> anything to "reorg" in a tablespace - recreate yes - reorg no
> Is this correct?
> 2 My plans would be to create new tablespaces using LMT and ASSM, then alter
> table move .. new tablespace. The LMT would minimizes future fragmentation
> and ASSM would benefit by using the alter table shrink; statement to alter
> the HWM in the future.
> Questions,
> 1 - Is there such a thing as online reorg of tablespaces and if so
> documentation on its use?
> 2 - Are there any issues that I'm overlooking in item 2
> Thanks
> Bob
> side note -dbms_refefination looks like what I've been told to look for but
> that is on the table level and not going to help because the tablespaces
> are DMT. I don't need to redef the tables I'm really looking to reclaim
> space from the tablespaces as well as putting the tables in LMT and ASSM
> mode
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Received on Tue Jun 28 2005 - 23:48:39 CDT

Original text of this message