I have a huge number of rows to insert into a table and I am not sure if LLBLGen does this in the most efficient manner possible.

ODP.Net provides a way to insert bulk data into a database in an efficient manner (using the ArrayBindCount). Does LLBLGen use it? I searched the source code and could not find any usage of ArrayBindCount !!

If yes, how do I make sure it does.

If not, is there any way to extend/change LLBLGen to do so?

check this thread: http://www.llblgen.com/tinyforum/Messages.aspx?ThreadID=3415

We don't support db specific ways to do bulk inserts. In general it's more efficient to use a small application / direct call to a DB api to do bulk inserts, especially if it's 1000's of rows. The reason is that the ways these API's work is often not through SQL but through lowlevel calls which surpass the necessity of using INSERT statements.