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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.
User-Defined Routines and Data Types Developer's GuideThe HCL OneDB™ User-Defined Routines and Data Types Developer's Guide describes how to define new data types and enable user-defined routines (UDRs) to extend HCL OneDB™.
Create user-defined aggregates
Extend existing aggregates
Extending a built-in aggregate

Extending a built-in aggregate

About this task

When you extend a built-in aggregate to include a UDT, you do not use the CREATE AGGREGATE statement because the aggregate itself already exists.

To extend a built-in aggregate:

Procedure

Develop support functions to overload the required operators.
Register each function with a CREATE FUNCTION statement.
For more information, refer to Registering a user-defined routine.

Results

After you register the support functions that overload the binary operators, you can use the built-in aggregates in an SQL statement.

For the syntax of the CREATE FUNCTION statement, see the HCL OneDB™ Guide to SQL: Syntax. For more information about how to write overloaded functions, refer to Routine overloading. For information about how to write functions in external languages, refer to the HCL OneDB DataBlade® API Programmer's Guide or the HCL® J/Foundation Developer's Guide.