How does Oracle Fast Refresh on Materizlied View for Joined Tables?

I wonder if anyone knows how oracle accomplish the task of Fast Refreshing MView for joined tables. I know it has logs for all changes happened on the underlying tables. However, let's say I have an MView as simple as Select * from T1, T2 where T1.C1=T2.C2 and T1.C2=1. When there is an insert on T1, how can Oracle tell if it needs to bring new rows from T2(that now should be in the MView) solely depending on change logs? Since the data in T2 are not changed themselves. And where does Oracle retrieve the row data? From the underlying table T2? What if change happened on T2 at the same time so that the data image of that row is no longer available? Apply undo?

So confused....

yyoodd Received on Fri Jul 25 2003 - 11:19:49 CDT