How to update a huge table efficiently

I need to update a 10 million record table everymonth. About 95% of the records will be updated. I am planning to load the update information to another table, then run a PL/SQL procedure to update the records that are already in the master table or insert the new records that do not exist in the master table. But, probably this will be extremely slow. Any suggestions on how I can go about doing this would be appreciated...

One idea that came to my mind is to get the rowid's of all the records in the master table, and then do a UNIX join on the keyed column and the rowids before I load the update data into the load table. This way, the load table will know what rowid's to update and so access will be much quicker. And for those new records that do not exist in the master table, therefore without a rowid, a simple insert will be performed.

I hope I was able to explain the problem..

Tansel Ozkan
Macrosoft, Inc. Received on Sat Nov 09 1996 - 00:00:00 CET