SQL & PL/SQL

We have used the 11g JDBC batch insert and have achieved insert rates of approx 7000 inserts per second in a sandbox environment.
We then tried populating a SQL table object and repeated the JDBC batch test but performance almost halved. Anybody know why?

We prefer to have a stored proc do the FORALL bulk inserts instead for more control of exception logging, row level exception logging etc.

What mechanism is the FASTEST (specific collection, nested table, temporary table, global temporary table etc) to pass the batch rows to a PL/SQL proc so it can bulk insert using FORALL?

Thanks in anticipation.