Re: UNTO TBS behavior in 9i

UNDO (both manual in 8i/9i/10g and auto in 9i/10g) entries are not before images of the blocks. They are actually change vectors containing only enough information to undo the change. For example, for an insert the undo vector is /*basically*/ just the row address and a delete indicator. There are index entries and block header entries (still not complete block images) as well.

For more details, you can read "Automatic Undo Internals" at http://www.optimaldba.com/papers/AutomaticUndoInternals.pdf

Regards,
Daniel Fink

NEW pop.tiscali.de wrote:
> Hi all,
>
> I think the retention setting is a red herring here. I *think* its a real
> basic issue. Someone posted the suggestion to use the append hint. I
> reckon this should work. You need to remember that for an insert the UNDO
> is a copy of the before image and if your inserting into 30G of blocks that
> have *some space* free, then all of these blocks need to be saved as UNDO.
>
> Maybe your PCTFREE settings need looking at. Has a lot of data been
> deleted - this would leave a lot of free blocks that will end up in the
> UNDO. Perhaps you can rebuild the table before the insert ...or even
> truncate it?
>
> Just ideas, hope they help
> Cheers
> Tony
>

--
http://www.freelists.org/webpage/oracle-l