Moving data from Materialized View to downstream application

Question

Database Version: 9i Release 2
I've created a Materialized View on a base table, the purpose of which is to capture data changes to send to a downstream application
(I've been advizsed to avoid using Streams for now until we upgrade to 10g)
I need to either:
a) Make that data available for another process to pick up and have knowledge of what it needs to pick up versus what it has already picked up
or
b) Send/Update a table or MV at a downstream MS SQL Server database (resides within our firewall)
Some notes/questions
I cannot change the structure of the underlying base table
On the MV I could capture a date-time which records each time a record is touched on the base table, the problem is that many of these updates are “meaningless” and I should not send such updates downstream
1.Is there a way I can timestamp/flag the records as they get inserted/updated on the MV? (potentially used by the pickup process to identify what it needs to pick up)
2. If I flag the records e.g. “needs pickup” – would it be ok to make the MV updateable so the process can then mark the records as “picked up”. Performance?
3. Can I create a trigger on the MV to write records to a secondary table as they are inserted/updated on the MV?
4. Could I use the MV log tables MLOG$ to help me in any way?
I’m guessing there is no way to do the following but:
5. Is there a way to include a column on a Materialized View but ignore it in terms of capturing changes. e.g. I have columns a,b,c,d,e on my base table, I want to include a,b,c in my Materialized View but I only want my MV to be updated if a or b is updated on base table. If only column c is updated do not send any update to MV
Many thanks for any insight

Answer 1

Yes I do have a unique identifier on each record in the base table and therefore also in the MV.
So now the Downstream application has to update some of its own database tables based on what is in the MV that I provide - just so I understand how would that work e.g.:
1. MV gets refreshed from my base table every minute
2. Some records are newly inserted and some simply updated
and this is the part I don't understand (I might be missing something obvious)....
3. Downstream application interrogates the MV every (say 1-2 minutes) and updates its own tables based on the data there.....but let's say MV contains 10,000 records and in the last minute 100 of those records have been updated and another 100 inserted - how will it know the 200 records it needs to pull?
Thanks again