No Support for lock-when-loaded on Sybase and DB2

For EJB 2.1 beans, the lock-when-loaded consistency level is implemented by placing update locks on the data corresponding to a bean when the data is loaded from the database. There is no suitable mechanism available on Sybase and DB2 databases to implement this feature. Therefore, the lock-when-loaded consistency level is not supported on Sybase and DB2 databases. See consistency in Sun Java System Application Server Platform Edition 9 Application Deployment Guide.