Flashback and transaction query very slow

Question

Hello. I was wondering if anyone else has seen transaction queries be really slow and if there is anything I can do to speed it up? Here is my situation:
I have a database with about 50 tables. We need to allow the user to go back to a point in time and "undo" what they have done. I can't use flashback table because multiple users can be making changes to the same table (different records) and I can't undo what the other users have done. So I must use the finer granularity of undoing each transaction.
I have not had a problem with the queries, etc. I basically get a cursor to all the transactions in each of the tables and order them backwards (since all the business rules must be observed). However, getting this cursor takes forever. From that cursor, I can execute the undo_sql. In fact, I once had a cursor that did "union all" on each table and even if the user only modified 1 table, it took way too long. So now I do a quick count based on the ROWSCN (running 10g and tables have ROWDEPENDANCIES) being in the time needed to find out if this table has been touched. Based on that, I can create a cursor only for the tables that have been touched. This helps. But it is still slow especially compared to any other query I have. And if the user did touch a lot of tables, it is still way too slow.
Here is an example of part of a query that is used on each table:
select xid, commit_scn, logon_user, undo_change#, operation, table_name, undo_sql
from flashback_transaction_query
where operation IN ('INSERT', 'UPDATE', 'DELETE')
  and xid IN (select versions_xid
              from TABLE1
              versions between SCN p_scn and current_scn
              where system_id = p_system_id)
  and table_name = UPPER('TABLE1')Any help is greatly appreciated.
-Carmine

Answer 1

Anyone?
Thanks,
-Carmine