RE: Online "tablespace" reorg ?
- From: Deepak Sharma <sharmakdeep_oracle@xxxxxxxxx>
- To: Paula_Stankus@xxxxxxxxxxxxxxx, bobmetelsky@xxxxxxxxxxx
- Date: Tue, 28 Jun 2005 20:59:46 -0700 (PDT)
We are using ASSM on most of our tablespaces in a ~6
TB DW without any issues so far, where tablespace size
varying from 1 G to 700G.
One instance where we used dbms_redef was to 'shrink'
tablespaces that had lot of unused datafiles. -
Basically,
1. Created new scratchpad tablespace.
2. REDEF All tables and moved to the scratchpad TS.
Used dbms_metadata to generate DDLs before redefining,
and using shell scripts to modify the tablespace info
etc. The redef was done using parallel (need to set
parallel dml at session level).
3. Dropped and recreated old tablespace (same name but
smaller # of datafiles)
4. REDEF all the tables back to the 'old' tablespace.
The process went without any issues except for few
staging tables that did not have a PK. In such cases,
after redefining, Oracle would add a hidden column,
that can either be 'left there', or in case you don't
want it, it needs to be dropped manually.
Thanks,
Deepak
--- Paula_Stankus@xxxxxxxxxxxxxxx wrote:
> Last I heard ASSM was buggy. I would search on ASSM
> in the archives.
>
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx
> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of
> Bob
> Sent: Tuesday, June 28, 2005 11:43 PM
> Cc: oracle-l@xxxxxxxxxxxxx
> Subject: Re: Online "tablespace" reorg ?
>
> A little more information of my environment . These
> are all DSS -
> Oracle 10.1.0.3.0 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" :)
>
> Thanks!
> Bob
>
> 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: oracle-l-bounce@xxxxxxxxxxxxx
> > [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of
> Bob
> > Sent: Tuesday, June 28, 2005 2:54 PM
> > To: oracle-l@xxxxxxxxxxxxx
> > 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
> > --
> > //www.freelists.org/webpage/oracle-l
> >
> > Privileged/Confidential Information may be
> contained in this message
> or attachments hereto. Please advise immediately if
> you or your employer
> do not consent to Internet email for messages of
> this kind. Opinions,
> conclusions and other information in this message
> that do not relate to
> the official business of this company shall be
> understood as neither
> given nor endorsed by it.
> >
> > --
> > //www.freelists.org/webpage/oracle-l
> >
> --
> //www.freelists.org/webpage/oracle-l
>
>
> --
> BEGIN-ANTISPAM-VOTING-LINKS
>
------------------------------------------------------
> Teach CanIt if this mail (ID 36578699) is spam:
> Spam:
>
https://dohsmsi01.doh.state.fl.us/canit/b.php?c=s&i=36578699&m=5f3be5d3d
> d52
> Not spam:
>
https://dohsmsi01.doh.state.fl.us/canit/b.php?c=n&i=36578699&m=5f3be5d3d
> d52
> Forget vote:
>
https://dohsmsi01.doh.state.fl.us/canit/b.php?c=f&i=36578699&m=5f3be5d3d
> d52
>
------------------------------------------------------
> END-ANTISPAM-VOTING-LINKS
>
> --
> //www.freelists.org/webpage/oracle-l
>
____________________________________________________
Yahoo! Sports
Rekindle the Rivalries. Sign up for Fantasy Football
http://football.fantasysports.yahoo.com
--
//www.freelists.org/webpage/oracle-l
Other related posts:
