I'm teaching JEE, especially JPA, Spring and Spring MVC. As I have not so much experience in large projects, it is difficult to know what to present to students about optimisation of ORM.

At the present time, I present some classic optimisation tricks:

• prepared statements (most of ORM implicitely uses it by default)
• first and second-level caches
• "write first, optimize later"
• it is possible to switch off ORM and send SQL commands directly to the database for very frequent, specialized and costly requests

Is there any other point the community see about other way to optimize ORM ? I'm especially interested by DAO patterns...