RE: Oracle 10g Rowid Question

From: Lex de Haan <lex.de.haan_at_naturaljoin.nl>
Date: Sat, 10 Sep 2005 14:49:33 +0200
Message-Id: <20050910124941.A19F41E9B92@turing.freelists.org>

there is a new ROWID format, for bigfile tablespaces -- but since that's a new 10g feature, that cannot be the reason for delays during a conversion of an existing database ...

apart from that, all data block do have slightly different block format bytes -- but that's only one update per block, not per row.

then, if you have bitmap indexes, there are some improvements implemented in those structures -- but as far as I remeber correctly, Oracle does the needed updates in a "lazy" manner. to be more precise, "lazy" is not a good term; you have to manually rebuild them yourself to benefit from less DML overhead. newly created bitmap indexes automatically use the new structure.

and of course I am overlooking some other reasons why things are slower the first time you access migrated data -- you can safely assume that they are for good reasons :-)

kind regards,

Lex.

Steve Adams Seminar http://www.naturaljoin.nl/events/seminars.html

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Deepak Sharma
Sent: Friday, September 09, 2005 18:41
To: Ric Van Dyke; oracle-l_at_freelists.org Subject: RE: Oracle 10g Rowid Question

Thanks.

One of the concerns someone raised is "All old rows in database will have slowness the first time they are read or updated due to conversion to 10g.". I am trying to find out if this indeed is true, and one of the things came to mind was if rowid format changed, which doesn't seem to be the case.

Deepak
- Ric Van Dyke <Ric.Van.Dyke_at_hotsos.com> wrote:

> If you are asking "has the rowid format changed in 10g?" then the
> answer is no.
>

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Received on Sat Sep 10 2005 - 07:51:47 CDT