Originally posted by DaPi
[B]So if an object has the NOLOGGING attribute, but only "normal" DML has executed against it (i.e. none of the above), all the entries exist in the log files to permit recovery.

Can such an object be restored & recovered?
yes, i don't think that there's a problem with that unless the object was actually created with the nologging option. Not sure what happens then ... I would imagine that the creation in nologging mode of a table would make it non-recoverable because even if no rows were initially inserted in it Oracle has no way of telling that.

http://download-west.oracle.com/docs...gy.htm#1004784

Can Oracle know if there are changes for which the log entries are missing (none in this case)?
Except where the object is created as nologging, i believe it knows all. If a bulk insert occured in nologging mode then I believe that the redo log marks the affected blocks with a code to indicate that their contents are indeterminate.
What is the status of the object if restored & recovered? (e.g. is an index USABLE?)
I think it's marked as corrupt in some way. The recommendation is to take an incremental or full backup after nologging operations. I have a feeling that RMAN is preferred for this because it can backup just the affected blocks -- I'm no RMAN expert though.