In this section, we discuss limitations and known issues in the MySQL Cluster Connector for Java APIs.

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. This means that ClusterJ does not handle foreign keys. While NDB tables do not support foreign keys, it is possible using JPA to enforce them programmatically.

Known issues in MySQL Cluster.  For information about limitations and other known issues with MySQL Cluster, see Known Limitations of MySQL Cluster.

Known issues in JPA.  For information about limitations and known issues with OpenJPA, see the OpenJPA documentation.

Known issues in JDBC and Connector/J.  For information about limitations and known issues with JDBC and Connector/J, see JDBC API Implementation Notes, and Connector/J: Common Problems and Solutions.