Hi,

We are using hibernate\EJB3 with a very complex DB scheme. This scheme contains more than 10 complex (interconnected) entities with composite primary keys (our primary key uses up to 5 columns and since this scheme is in production, changing it is impossible) and in our C++ based application, we can handle this large amount of data (>=20000 entities). We now switched from C++ to Java, followed all recommended tips (we're just reading entities: so we can safely set read only query hint, set flush mode to commit) and the performance loss is more than a factor of 15! So we would like to investigate if others have tried to use composite primary keys and if you were satisfied with the performance. Or if there are ways to improve the performance of hibernate when using composite primary keys.

Best regards,
Matthias

Do you know where most of the time is spent? I wouldn't expect much difference from C++ to Java in such an application, but using hibernate is probably a big difference. I encourage you to profile the application and look at the generated sql statements. You might need to enable some L2 caching, and/or try to lazy fetch some dependent data. In my personal experience hibernate usually performs poorly when it is used with complex database and no proper caching.



Farzad-