while doing some basic startup perf testing the following were found - this issue is mainly to track what I find, and then fix it:
Initial tests where 100 classes, 30 sec for buildSessionFactory
setting hibernate.cglib.use_reflection_optimizer false and it is 10 sec for buildSessionFactory.
(maybe we should autodetect which jdk we are running on and disable it per default for 1.4/1.5 - needs to validate runtime impact)
Another (22%) time stealer is the discovery of getter/setters - in worst case it iterates over all declared methods per property.
(alternatively we could cache/sort this list or make a more efficient implementation if a class only contain default property accessors)
Other 20% of the time is done in net.sf.cglib related classes for build time enhancement.
The rest of the time is Configuration creation (can be cached) and other iteration code.
(p.s. don't take the % numbers as hard values - these are definitly affected by how many methods/classes you have; this underlying tests
is done on pojos with a "high" method count (approx 100)