Joins: With ClusterJ, queries are limited to single tables. This is not a problem with JPA or JDBC, both of which support joins.

Database views: Because MySQL database views do not use the NDB storage engine, ClusterJ applications cannot “see” views, and thus cannot access them. To work with views using Java, you should use JPA or JDBC.

Relations and inheritance: ClusterJ does not support relations or inheritance. Tables are mapped one-to-one onto domain classes, and only single-table operations are supported. NDB tables support foreign keys, and foreign key constraints are enforced when using ClusterJ for inserts, updates, and deletes.

TIMESTAMP: Currently, ClusterJ does not support the TIMESTAMP data type for a primary key field.