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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™.
Opaque user-defined data typesThis section describes how to use opaque user-defined data types (UDTs). This section describes the default SQLData interface and how to override the default.
Using the SQLData interfaceTo implement a complete UDT in Java™ code, you must supply a set of data-formatting methods that convert to and from the various representations of the data type. These methods perform input and output operations for the data type such as converting text input to the internal structure that the database server uses.
Default input/output routinesBecause this interface uses Java™, all the SQL I/O support functions are predefined when you register the UDT. You only need to supply the required SQLData implementation.

Default input/output routines

Because this interface uses Java™, all the SQL I/O support functions are predefined when you register the UDT. You only need to supply the required SQLData implementation.

HCL OneDB™ supplies extensions to the Stream arguments of SQLData methods to suit various uses. With these extensions, you can build I/O functions for a new Java UDT. All that you must do to implement any of the required function sets is select the Stream type.

HCL OneDB also supplies default Input and Output processing methods in Java code that are used to implement all UDT I/O operations. The database server contains these default I/O methods and executes them just like any other Java UDR. These methods use information in the SQL UDR definition to select the correct Streams and instantiate the right user-defined type objects at execution time.

The circle class example illustrates the use of the SQLData interface.