Space wasted because of automatic undo management

Let's say I am using traditional rollback segments. For a small database I would create 4 segments, each 100 MB in size, and set OPTIMAL to 100 MB. All 4 segments will be in the same tablespace and in the same datafile, so initial datafile size will be 400 MB. It may grow if there is a large transaction, but eventually the transaction will complete, rollback segment shrink back to OPTIMAL size, and the datafile could be resized back to 400 MB. So the space is used efficiently and not wasted.

It appears that with automatic undo management the space is being used very inefficiently. Oracle creates additional extents all over the place, with total disgregard for disk space. There are huge chunks of empty space between individual extents. I am thinking about switching back to traditional rollback segments.

Any thoughts?

Thanks

Sev Received on Thu Mar 31 2005 - 20:07:54 CST