Re: Rollback Segs

Paul,
Oracle uses rollback segments to provide a read consistent image to users when data is being changed. Before changing a piece of data oracle copies that data to a rollback segment so other users don't have to wait for the user changing the data to commit. They also provide for rollback in case of data entry error. The errors you are getting (cannot create extent) are probably because you don't have enough space allocated for your rollback segments. As to what parameters to use and how to size rollback segments, there is no easy or correct answer. You will have to read about rollbck segments and determine that yourself for your situation. It is recommended that you use one rollback segment per 4 transactions Hope that helps
Venkat

Paul Bennett wrote in message <34EAFBD7.F62A7E65_at_cc.gatech.edu>...
>I am having trouble understanding how rollback segments work in oracle.
>How do i determin how many to create and what paramaters to use when I
>do create them? How do I prevent getting rollback errors (can't create
>extent) and so forth? I have about 600 megs worth of data and if I try
>to expand a column or something I get rollback segment errors.
>
>-- Paul
>
Received on Wed Feb 18 1998 - 00:00:00 CST