In other words, you saw the first of 5 points and completely ignored the rest of what I said. Inserting records through DBI will always be slower than the bulk-loader provided with the RDBMS. Often, 100x slower. Therefore, the proper solution is to prepare a file for the bulk-loader.

You were worried about auto-incrementing primary keys. The solution in MySQL is to insert a NULL. In Oracle, the solution is different. Sybase has a third solution.

You were worried about unique keys. Bulk-loaders provide a mechanism for solving this problem. Alternately, you should use a hash because that's the way to unique-ify a list of values.

Open your head!