Answer by Triskelion for feeds module cannot handle csv files exceeding 8gig?

Not many things could handle this. For importing massive amounts of information from an external database, you are better off to do it using Feeds and Feeds Database. Even then you will probably be best to do it progressively in chunks.

If you are intent on using csv files, then export them from your original database using limited queries and create several files:

SELECT ......... LIMIT 100 OFFSET 0;
SELECT ......... LIMIT 100 OFFSET 100;

and so on until you have all the information.