[11g] DIRECT-MODE insert in a partitioned table

Hi,

I would like to know if an INSERT with DIRECT-MODE (by using APPEND hint) in a partitioned table cause a full table lock or only for the partition concerned during the insert dml ?

INSERT /*+ APPEND */ INTO PRODUCTS SELECT * FROM NEW_PRODUCTS where PARTITION_KEY = '2012';

What are the disadvantages of using DIRECT-PATH in INSERT DML ?

Is it useful to use nologging mode to improve performances ?

Best regards.

GD.