Re: [Q] undo tablespace did not release space?? (less quoting)

From: Daniel Fink <Daniel.Fink_at_Sun.COM>
Date: Mon, 29 Mar 2004 08:18:38 -0700
Message-id: <40683E4E.1FCA1D6E@sun.com>

The allocation algorithm in 9i is such that a 'full' tablespace is
not necessarily a bad thing. When a transaction needs additional undo space, it will acquire space from the existing undo segments,
until then it will keep the undo entries around. IIRC, SMON will periodically clean up the undo tablespace. The bottom line is to not
worry about a full tablespace, only worry about 1555 errors.

As for the automatic v. manual (rollback) debate, at Hotsos a very
solid source said that AUM is not recommended for high-volume OLTP
systems. As this is not the 'official' Oracle stance, I won't name
names, but I respect this person's opinion and find myself in agreement.

In the meantime, I suggest you acquire the only guaranteed AUM Management tool...a good bottle of Scotch!

Regards,
Daniel

Paul Drake wrote:

> > We have ORACLE 9ir2 running on LINUX server. I
> > check
> > Tablespace and found undo tablespace almost full for
> > long time. It did NOT release space. The undo
> > tablespace setup are undo_management=AUTO
> > undo_retention=900. Does anyone know why it don't
> > release space?
> >
> > Thanks.
>
>
> After attending Dan's presentation at RMOUG, I'm
> thinking of reverting to rollback segments for loading
> situations (if not entirely).
>
>
> Pd

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Received on Mon Mar 29 2004 - 09:15:25 CST