Application Server support for CMP includes:
Full support for the J2EE v 1.4 specification’s CMP model.
Support for commit options B and C for transactions, as defined in the Enterprise JavaBeans Specification, v2.1. See Commit Options.
The primary key class must be a subclass of java.lang.Object. This ensures portability, and is noted because some vendors allow primitive types (such as int) to be used as the primary key class.
The Application Server CMP implementation, which provides:
An Object/Relational (O/R) mapping tool that creates XML deployment descriptors for EJB JAR files that contain beans that use CMP
Support for compound (multi-column) primary keys
Support for sophisticated custom finder methods
CMP runtime support. See Configuring the CMP Resource.
Application Server performance-related features, including:
Version column consistency checking
Relationship prefetching
Read-Only Beans
For details, see Performance-Related Features.