Re: Exporting a large table

From: Joel Garry <joelga_at_pebble.ml.org>
Date: 10 Apr 1998 15:25:46 -0700
Message-ID: <6gm69a$uv6$1@pebble.ml.org>

In article <352CE1CC.167E_at_pathcom.com>, Hitesh <hpatel_at_pathcom.com> wrote:
>I am getting the following oracle error message during an
> export of a very large table which is not being updated or
> queried during the process. (The table has used up about
> 2 gig of database space and I think it has 10 million+ rows)
>
> The process lasted for 3.5 hrs and then I got the error
> message.
>
> EXP-00008: ORACLE error 1555 encountered
> ORA-01555: snapshot too old (rollback segment too small)
>
> Any ideas how to dump this table?
>
> Thanks in advance.
> Hitesh Patel

From some doc about error messages:

   Insufficient Rollback Segments: A long running query may not be able to reconstruct the snapshot of    the blocks it is reading because the rollback data is not available. This can happen when the database    has many transactions that are changing data, then committing or rolling back. The rollback data can    be overwritten if the rollback segments are too small for the number and size of the changes being    made.

Basically, the transaction is writing over the first part of itself before completing. You need to have a larger rollback segment - perhaps a dedicated big one just for this export. Or else use select statements to get parts of the table into flat files. Or partition the file and use exp by partition. --
These opinions are my own and not necessarily those of Information Quest

jgarry@eiq.com                           http://www.informationquest.com

http://ourworld.compuserve.com/homepages/joel_garry "See your DBA?" I AM the @#%*& DBA! Received on Fri Apr 10 1998 - 17:25:46 CDT