Application Server Support for CMP

Application Server support for EJB 2.1 CMP beans includes:

• Full support for the J2EE v1.4 specification’s CMP model. Extensive information on CMP is contained in chapters 10, 11, and 14 of the Enterprise JavaBeans Specification, v2.1. This includes the following:

  • Support for commit options B and C for transactions. 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 the following:

  • 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.

  • Standards-based query language (EJB QL).

  • CMP runtime support. See Configuring the CMP Resource.

• Application Server performance-related features, including the following:

  • Version column consistency checking

  • Relationship prefetching

  • Read-Only Beans

  For details, see Performance-Related Features.