ORMs basically comes from "lazy" programmers not wanting to learn SQL and proper database schema design and wanting something "that just works" instantly with little thought effort... Optimizations and handling of large data sets are some of the problems with ORMs. However, in our case we decided to use an ORM anyways because each UPDATE/DELETE/INSERT had to be signaled out to some lowlevel code, communicating with hardware. If we hadn't used an ORM (with overloaded save-methods) the user would have to keep track of all changes himself and signal the hardware manually, so in our case this was fine (we also didn't manage large data volumes)...