>
> And it's been a while; but I thought transactions like that could
> overflow rollback segments in that other database.
>
ORA-01555: snapshot too old: rollback segment number string with name
"string" too small
Cause: Rollback records needed by a reader for consistent read are
overwritten by other writers.
Action: If in Automatic Undo Management mode, increase the setting of
UNDO_RETENTION. Otherwise, use larger rollback segments.
In 10g you can do
ALTER TABLESPACE UNDO_TS2 RETENTION GUARANTEE;
which will automgically grow the undo tablespace until you run out of
disk space or the transaction ends.