Hibernate version:
2.1.4

We (are starting to) use Hibernate in an application that has to co-exist with its legacy counterpart. To describe further, we are writing an EJB-based application that accesses the legacy (Informix 7.24) database (updates, inserts, deletes, selects etc...). Also, the legacy application written in 4GL accesses the SAME database and does insert, update, delete, select etc...

Is there anything that I should be aware of while using Hibernate in this situation? If you can point me to the DO's and DONT's, it would be really helpful.

If you use hibernate version (pesimistic locking) Tou wiil have problem because leagcy app don't update version, probably

regards

You mean *optimistic locking*.

Also be sure you understand the implications of using a second-level cache in this environment.

yes , optimistic. I'm sorry

1. Is second-level cache optional?

2. Is it off by default?

3. Can I control the 2nd level cache on a table-by-table basis? For example, if I want, can I turn it ON to only those tables which are not updated by the legacy app?

Regarding the versioning: Without adding the version column to the tables, is there another way to handle Optimistic Locking in hibernate? For example, load the data and compare before updating automatically? If so, can you point me to the right resource?

Sorry for asking too many questions. Hibernate has been making our life easier and don't want to get rid of it at this stage, just because we have to co-exist with the legacy application.

1- yes
2- yes
3- just configure class by class

and i'll add
4- read reference guide and there are a lot of info about caching and lockink in hibernate in action