Re: experience with convert Dictionary managed tbs to LMT with dbms_space_admin

Hi, Lex,

   Rebuild would be nice but as I said before, our database is pretty big (1TB-3TB) and it is impossible to rebuild it without days's downtime. The maximum downtime is 2 hours for us. So we have to live with current.    

 ZimSbait, the thing you mentioned is critical for production box. I am not sure what you was your exact problem. I don't have much experience with the converted local managed tablespace, according to metalink, it use the same extent management policy as dictionary managed tablespace, so what is the difference?

Thanks   

On 6/30/05, Lex de Haan <lex.de.haan_at_naturaljoin.nl> wrote:
> LMTS is a *must* ... DMTS is dead. I only know good experiences.
> however, if you have the chance, create and populate the new LMTS tablespaces
> from scratch --
> don't migrate existing tablespaces. that leads (at the least) to suboptimal
> bitmap storage.
>
> kind regards,
>
> Lex.
>
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> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On
> Behalf Of zhu chao
> Sent: Thursday, June 30, 2005 16:45
> To: Oracle-L_at_Freelists. Org (E-mail)
> Subject: experience with convert Dictionary managed tbs to LMT with
> dbms_space_admin
>
> Hi, All,
> We have some pretty big OLTP database suffer from ST enqueue contention
> (size range from 1TB-3TB), because we use dictionary managed tablespace and
> without proper extent size when table/index/context index got created.
> Now some indexes have tens of thousands of extents and whenever we drop some
> unused objects(like not used index via index monitoring), we suffer from ST
> enqueue, even during normal business operation time.
>
> We plan to use dbms_space_admin to convert existing DMT tbs to LMT tbs, and I
> already did some test on test box and it seems very good and pretty fast.
> Before do any change in production, ,I would like to ask you guys, if anyone
> has used it on big database and have any good/bad experience with it.
>
> Thanks for sharing.
> Regards
>
>
> --
> Regards
> Zhu Chao
> www.cnoug.org
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Regards
Zhu Chao
www.cnoug.org
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