Home
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® API Function ReferenceThe HCL OneDB™ DataBlade® API Function Reference describes the DataBlade® API functions and the subset of functions that the DataBlade® API supports.
Function descriptionsThis section gives comprehensive reference information about the functions that are valid within DataBlade® API modules. It lists the function descriptions in alphabetical order, with syntax, usage information, and return values for the functions.
The mi_class_numvp() functionThe mi_class_numvp() function obtains the number of active virtual processors (VPs) in a VP class.

The mi_class_numvp() function

The mi_class_numvp() function obtains the number of active virtual processors (VPs) in a VP class.

Syntax

mi_integer mi_class_numvp(VPclass_id)
   mi_integer VPclass_id;

VPclass_id

A VP-class identifier for the VP class whose number of active VPs the function is to return. This argument can be either of the following values:

A valid VP-class identifier: Obtains the number of active VPs in the specified VP class.
MI_CURRENT_CLASS VP-class constant: Obtains the number of active VPs in the VP class of the current VP.


Valid in client LIBMI application?	Valid in user-defined routine?
No	Yes

Important: This advanced function can adversely affect your UDR if you use the function incorrectly. Use it only when no regular DataBlade® API function can perform the task you need done.

Usage

The mi_class_numvp() function returns the number of active VPs in the VP class that the VPclass_id argument specifies. An active VP is a VP that is currently executing a task. The number of active VPs is initially the value assigned with the num option in the VPCLASS configuration parameter. For example, suppose you have the following VPCLASS configuration parameter:

VPCLASS=newvp, num=3, max=6

The mi_class_numvp() function returns the value of 3 when it receives the VP-class identifier for the newvp VP class. However, if the DBA dynamically adds or removes VPs, the value that mi_class_numvp() returns might not coincide with the num option. You can obtain a VP-class identifier with the mi_vpinfo_classid() or mi_class_id() function.

This function is useful to determine if the current VP is part of a single-instance VP class. For such a VP class, the mi_class_numvp() function returns a value of 1.

Tip: To obtain the maximum number of VPs defined for the VP class (by the max option of the VPCLASS configuration parameter), use the mi_class_maxvps() function.

For information about how to obtain information about VPs and VP classes, see the HCL OneDB™ DataBlade API Programmer's Guide.

Return values

>=0: The number of active VPs in the VP class associated with the specified VP-class identifier.
MI_ERROR: The function was not successful or that the specified VP class does not exist.