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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® 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_module_lock() functionThe mi_module_lock() function prevents the shared-object file of the current UDR from being unloaded.

The mi_module_lock() function

The mi_module_lock() function prevents the shared-object file of the current UDR from being unloaded.

Syntax

mi_integer mi_module_lock(lock_flag)
   mi_integer lock_flag;

lock_flag

The value to set the module-lock flag for the shared-object file of the current UDR. This flag can have the following values:

MI_TRUE: The value sets the module-lock flag to prevent the routine manager from unloading the shared-object file.
MI_FALSE: The value unsets the module-lock flag to indicate that the routine manager can unload the shared-object file when necessary. This action does not force an unload of the shared-object file.


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_module_lock() function sets the module-lock flag to the value that lock_flag specifies. The module-lock flag indicates whether to lock the shared-object file in the memory of the database server. When the module-lock flag is MI_TRUE, the routine manager does not allow the shared-object file to be unloaded for any reason. This function is useful for preventing arbitrary unloading of shared-object files, which necessitates reinitialization the next time any UDR on the shared-object file is used.

Return values

MI_OK: The function was successful.
MI_ERROR: The function was not successful.