Question

I have 5 MySQL InnoDB tables: Test,InputInvoice,InputLine,OutputInvoice,OutputLine and each is mapped and functioning in Hibernate. I have played with using StatelessSession/Session, and JDBC batch size. I have removed any generator classes to let MySQL handle the id generation- but it is still performing quite slow.
Each of those tables is represented in a java class, and mapped in hibernate accordingly. Currently when it comes time to write the data out, I loop through the objects and do a session.save(Object) or session.insert(Object) if I’m using StatelessSession. I also do a flush and clear (when using Session) when my line count reaches the max jdbc batch size (50).

1. Would it be faster if I had these in a ‘parent’ class that held the objects and did a session.save(master) instead of each one?
2. If I had them in a master/container class, how would I map that in hibernate to reflect the relationship? The container class wouldn’t actually be a table of it’s own, but a relationship all based on two indexes run_id (int) and line (int).
3. Another direction would be: How do I get Hibernate to do a multi-row insert?

Answer 1

The final solution for me was to use voetsjoeba’s response as a jumping off point.
My hibernate config uses the following options:

hibernate.order_inserts = true
hibernate.order_updates = true

• I changed from using Session to
  StatelessSession

• Re-ordered the
  Java code to process all the elements
  in a batch a table at a time. So all
  of table x, then table y, etc.

• Removed the <generator> from each
  class. Java now creates it and
  assigns it to the object

• Created logic that allowed me to determine if just
  an id was being set and not write
  ’empty’ lines to the database

• Finally, I turned on dynamic-insert
  for my classes in their hibernate
  definitions like so: <class name="com.my.class" table="MY_TABLE" dynamic-insert="true">