Transactions vs Decision support RB seg size

I have a large amount of data (several million rows) that I want to put into Oracle (currently in a number of separate dbf files). I know that to put the data into the data base I'll need some fairly large rollback segments. People will primarily use this data for decision support and summaries, but will typically be using it very little to update. Updates will typically occur every couple of months to quarterly and won't involve the entire data base. My basic question is, will I need large rollback (or temporary, etc) segments to support mainly joins for select queries, if I'm not doing inserts, deletes, etc.? I know I'll need them from time to time to support major updates, but would I be better off using several small rbs and then creating a larger one from time to time to do the updates?

Second question. I have the default data base installed and working on an NT box. Do I really need to have a separate user space for each user for this same data base or could everyone use DEMO (or another user) to access the same tables?

Thanks in advance.

Remove the NOBESPAMMIN from email address for email replies. Received on Tue Mar 17 1998 - 00:00:00 CST