When i update the hibernate from 2.03 to 2.10,The below code get a performance problem.

// construct query here

for(int i = 0; i < params.size();i ++) {
// set the paramer for the query
query.list();
......
}

when the size is 200, in 2.03 it only need 1000 ms , but in 2.10, it spend
20*1000ms since mostly of query get nothing! since mostly of query cannot get object, it will not the problem of new cglib
I use the default configuration . I think the default configuration of new version don't use preparestatment correctly. i try to set the batch size , but dont' work well.

I also try to insert /update record in a cycle, it also spent more time than 2.03.
Is there anyone can help me?

Hibernate internal connection cache don't support prepared statement anymore. It is not intended to be used in production mode.
Use a good connection cache (app server, c3p0, dbcp, ...)