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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for HCL OneDB™.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in HCL OneDB™ databases.
J/Foundation Developer's GuideThe HCL® J/Foundation Developer's Guide describes how to write user-defined routines (UDRs) in the Java™ programming language for HCL OneDB™.
Create Java™ user-defined routinesA user-defined routine (UDR) is a routine that an SQL statement or another UDR can invoke. UDRs written in Java™ code use the server-side implementation of the HCL OneDB™ JDBC Driver to communicate with the database server.
Debugging and tracingAs with a UDR written in C, a UDR written in Java™ code might generate the SQL messages for UDR and DataBlade® API errors when it executes. UDRs written in Java™ code adopt the HCL OneDB™ JDBC Driver error-reporting mechanism as well.

Debugging and tracing

As with a UDR written in C, a UDR written in Java™ code might generate the SQL messages for UDR and DataBlade® API errors when it executes. UDRs written in Java code adopt the HCL OneDB™ JDBC Driver error-reporting mechanism as well.

The UDR throws an SQLException in case of an execution error such as a failed OneDB JDBC Driver call. The routine manager detects such exceptions and translates it into a normal UDR error message.

In addition, the UDR can generate Java trace outputs and stack dumps at run time. These additional Java messages are written to the JVP log file. The JVP log file is separate from the main database server log file, online.log. No JVP-specific messages appear in the database log. The JVP log file is intended to be the main destination for logging and tracing messages that are specific to the JVP and the UDR. This log is essential for HCL support to perform debugging efforts. You should preserve it when possible.