I am parsing a ~2GB file, deserialising into POJOs using Jackson JSON and persisting to a MySQL DB using Hibernate. I clear and flush the session regularly as recommended for batch processing.

I cleared all old data last night and ran my application. All worked well but it seems to be using a huge amount of disk space until the transaction is committed.

Is there anything I can do to reduce this? I was thinking of committing in sections but don't think this is ideal.

I have a graph of disk space usage but don't think I can attach an image.

Graph of disk space usage, starts at 17:00...



https://www.dropbox.com/s/pau564zp4oi5w1l/FreeSpace.jpg