why does an insert procude rollback segment data?

Hi Gurus,
As the subject explains , i am new with oracle. I am sorry if the question is very simple. The mechanism uses a rollback segment (or undo) concept , which stores before-images , and redo log concept which stores transaction information. Am i right? Guessing that i am right , my question comes: Does an insert statement needs rollback segment? I dont think so because insert statement does not change a block , but creates a new one so there is no before image record. If so , what is the before image of an insert statement?

Kind Regards,
hope Received on Mon Sep 29 2003 - 09:27:09 CDT