Sun GlassFish Enterprise Server v2.1.1 Developer's Guide

No Support for lock-when-loaded on Sybase

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 databases to implement this feature. Therefore, the lock-when-loaded consistency level is not supported on Sybase databases. See consistency in Sun GlassFish Enterprise Server v2.1.1 Application Deployment Guide.