This limitation is applicable to applications that makes use of WebSphere® extensions and bindings. However, if your application does not make use of any of the WebSphere extensions and bindings; and only implements code from the J2EE specifications, than this limitation is not applicable. Hereafter in this limitation, the term "application" defines an enterprise application that makes use of WebSphere extensions and bindings.
When an application is coming from a newer version of the product, you cannot run code generation tools from an older version of the application server. For example, if an EJB application is developed in version 7.5 of this product, you cannot run ejbDeploy command from WebSphere Application Server v6.1.
The application developed in the newer version of the product may include additional functions or fixes that are not recognized in older code generation tools.
Instead, use the code generation tools from the newer version of the product to package the application as a deployable enterprise artifact (EAR) file. The newer version of the development products provide binary compatibility support to older runtime servers as long as the server supports the J2EE specification level and technology used in the application.
If you have a mixed strategy, you must follow the following rule when using EJB queries: If a bean is mapped to its parent table, then all of its descendants, siblings and descendants of its siblings must follow the same strategy. For example, given a hierarchy illustrated below, if ChA1 is mapped to the same table as ChA, then ChA3, ChA2 and ChA4 must also be mapped to the same table.