Whenever you have a really large amount of data to insert into a table, it is much better and faster to use a loading utility that is native to the database server. (In the case of Oracle, this would be a tool called sqlload, or something similar to that -- I don't know the exact spelling of the tool name in Oracle 9i.)

It would be most effective to use a simple Perl script to create the text stream that will serve as input to the native dbms import tool, so that you have a chance to make sure that the input won't involve any really hazardous mistakes -- i.e. errors in the data that the dbms tool might find acceptable even though they are errors.

I haven't done a recent systematic benchmark of Perl/DBI vs. sqlload, but the last time I had occasion to compare the two, doing row inserts via Perl/DBI was orders of magnitude slower than using sqlload.