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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™.
Develop a user-defined routine
Plan the routine
An iterator function
An iterator function in the FROM clause of a SELECT statement
Run parallel queries

Run parallel queries

If you are running queries in parallel using the HCL OneDB™ parallel database query (PDQ) feature and the iterator UDR in the FROM clause is not parallelizable, query parallelism is turned off for the SELECT query. However, if the iterator UDR in the FROM clause is parallelizable and no other factors disable the query parallelism, the query can run in parallel. When PDQ is on, functional tables are treated as single non-fragmented tables.

In the following example, the GROUP BY and aggregation operations can be run by multiple PDQ threads and the fibseries() function can be run by a secondary thread.

SELECT col1,col2, COUNT(*) FROM TABLE (FUNCTION fibseries(10)) 
tab1(col1),tab2
GROUP BY col1,col2;

Refer to your HCL OneDB Performance Guide for information about running queries in parallel.