Master DB feeds another - how to synch?

Hi all,

I am wondering what the most efficient way to accomplish a task might be.
My database has a bunch of customers, orders, and other data in it. Another database, which is not mine, needs to be the feed for the customers and the orders. However, the tables are structured completely differently.
At the moment, I use a java program to query the master DB (loop through all records) for all the data I need and put it where I need it. Some of this data is stuff I change the form of, like a numeric to a string (if it's someone from the US, the master DB has a 1. I change that to the string "US"). That program then must loop through all my records and remove things that were deleted from the master. This process is time consuming and resource intensive, as it has to loop through all the records (for specified tables) in both databases. Can anyone tell me a better way?
If a customer or order is new, I must add it. If they have changed, I must update. If they have been deleted, I must delete.

Both DBs are Oracle 8i on Solaris. I do not own the master and can't add triggers or change it in any way. I have query permissions only.

TIA

     ~kaeli~
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