Re: Need advice on import with auto undo
- From: LiShan Cheng <exriscer@xxxxxxxxx>
- To: "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 9 Feb 2006 09:02:24 +0100
Hi
11GB dump file doesnt mean you need a large UNDO, remember by default a
commit is issued after each table import. You must know your largest table
size and not the dump file size.
You can increase undo_retention sure, just that by doing so you will need
more space, if space is not an issue I would let the undo autoextend (with
maxsize on) with several datafiles and in the import use
RESUMABLE
RESUMABLE_NAME
RESUMABLE_TIMEOUT
So if undo is full you can simply add more space and resume the import.
Regards
LSC
On 2/9/06, Michael Ray <topshot.rhit@xxxxxxxxx> wrote:
>
> I'm used to the old (8i) way of handling rollback. Oracle seems to be
> pushing automatic undo management (AUM) so I get an undo tablespace
> when I create a 10g starter database to dump my import into.
>
> Normally, I'd create a single large rollback to do the import. From
> Note:135090.1 I see that "Having several UNDO tablespaces available in
> the database provides the possibility to switch and use a different
> tablespace with smaller or larger global size for different purposes
> of usage, such as OLTP, BATCH." This makes it sound like I can create
> a large Undo tbs and activate it for the import and switch back when
> done. My dump file is 11+ GB so I'd need one a bit larger I'd guess.
>
> I was also wondering if I could tweak the undo_retention init
> parameter. It has been using the default (900?) so far, which doesn't
> seem to be very friendly for imports. How low can it be set? My main
> goal is to minimize import time.
>
> I suppose if all else fails, I can use my own create db script, do the
> import the old fashioned way and then worry about converting to AUM
> afterward.
>
> Shalom,
> Michael Ray
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
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