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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 an opaque data type
Opaque data types
Support functions
Aggregate functions

Aggregate functions

An aggregate function returns one value, such as SUM or AVG, for a set of queried rows. You can extend the built-in aggregates to provide for your opaque data types. You can also create new, special-purpose aggregate functions.

For information about how to extend the built-in aggregates, refer to Extend existing aggregates. For information about how to create new aggregate functions, refer to Create user-defined aggregates. For information about how to use aggregate functions, see the Expression segment in the HCL OneDB™ Guide to SQL: Syntax.