Re: Troubleshooting ORA-01555 while using AUM

"VC" <boston103_at_hotmail.com> wrote in message news:3ux0c.151075$jk2.589509_at_attbi_s53...
> Pls. see below:
>
> "Tech Geek" <Tech_Geek_at_Gawab-IHateSpam.com> wrote in message
> news:6Qw0c.19711$6K.4704_at_nwrddc02.gnilink.net...
> >
> > --- My bad. Please read as zeros, instead of non-zeros.
> >
> >
> > > Could you supply more information about under exactly what
> circumstances
> > > the 1555 is happening in your case ?
> >
> > This database is being used by end-users for short transactions 24x7
and
> > some adhoc batch jobs, which update/insert new records and also does
some
> > SELECTS. Mostly, the batch jobs and the daily export job run at time of
> the
> > day, ends up with Ora-1555.
>
> I prefer to use StatsPack to figure out how large the undo TS should be
but
> let's try and use the V$UNDOSTAT for the same purpose.
> Let's forget about those two columns (UNXPSTEALCNT/UNXPSTEALCNT) and take
> look at 'undoblk' and 'maxquerylen'.
>
> Assuming the max value of undoblk is 10000 8K blocks in 10 minutes (0.13
> MB/sec) and the max value in 'maxquerylen' is 7200 sec, then _each_ of
your
> undo segments should at least be 940 MB in order to avoid the 1555 error.
> For ten segments, it'll amount to 9.4 GB.
>
> VC
>

Don't know, if it helps, I have about 13G. The export completes or fails almost after 40 minutes. It's still puzzles me.

Thanks
TG

>
Received on Sun Feb 29 2004 - 21:45:56 CST