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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.
DataBlade® Developers KitThe DataBlade® Developers Kit (DBDK) guides contain information about the tools you can use to develop and package DataBlade® modules, which extend the functionality of HCL OneDB™ databases.
DataBlade® Developers Kit User's GuideThe HCL OneDB™ DataBlade® Developers Kit Users Guide describes how to use OneDB® DataBlade® Developers Kit (DBDK) tools to develop and package DataBlade® modules.
Programming DataBlade® module routines in CThis section contains information to help you edit and compile C language source code generated by DataBlade®.
Edit statistics routines in statistics.c
The statistics collection functionThe OpaqueStatCollect() function collects statistics (minimum value, maximum value, and distribution information) for the Opaque opaque data type when a user executes the UPDATE STATISTICS statement in medium or high mode.

The statistics collection function

The OpaqueStatCollect() function collects statistics (minimum value, maximum value, and distribution information) for the Opaque opaque data type when a user executes the UPDATE STATISTICS statement in medium or high mode.

The generated code

The OpaqueStatCollect() function calls the Opaque_SetMinValue(), Opaque_SetMaxValue(), and Opaque_SetHistogram() functions.

BladeSmith generates complete code for the OpaqueStatCollect() function. The OpaqueStatCollect() function is an iterator that processes each row in a table. It compiles statistical information by calling the Opaque_SetMinValue(), Opaque_SetMaxValue(), and Opaque_SetHistogram() functions. The OpaqueStatCollect() function stores statistical information in a multirepresentational type.

Customize the code

You must understand your data and how users will query it to create meaningful statistics. BladeSmith generates statistics code under the assumption that the minimum, maximum, and distribution of values are appropriate for your opaque data type; however, they might not be. In that case, you must rewrite the OpaqueStatCollect() function to call other functions that you provide.