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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_lo_decrefcount() functionThe mi_lo_decrefcount() function decrements the reference count of a smart large object.

The mi_lo_decrefcount() function

The mi_lo_decrefcount() function decrements the reference count of a smart large object.

Syntax

mi_integer mi_lo_decrefcount(conn, LO_hdl)
   MI_CONNECTION *conn;
   MI_LO_HANDLE *LO_hdl;

conn

This value is one of the following connection values:

A pointer to a connection descriptor established by a previous call to mi_open(), mi_server_connect(), or mi_server_reconnect().

A NULL-valued pointer (database server only)

LO_hdl

A pointer to the LO handle.


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

Usage

The mi_lo_decrefcount() function is useful for manually tracking multiple references to the same smart large object. Typical use of this function is in the destroy() support function of an opaque data type that contains smart large objects. Use the mi_lo_decrefcount() function in the destroy() support function to decrement the reference count of the smart large object that is being deleted by one, as follows:

If the opaque type does not have an lohandles() support function, you must use the mi_lo_decrefcount() function in the destroy() support function of the opaque type.
If the opaque type has an lohandles() support function, do not use the mi_lo_decrefcount() function in the destroy() support function. The database server automatically decrements the reference count when it executes the lohandles() support function at destroy time.

Server only: The mi_lo_decrefcount() function does not need a connection descriptor to execute. If your UDR does not need a valid connection for other operations, you can specify a NULL-valued pointer for the conn parameter to establish a NULL connection. For information about the advantages of a NULL connection, see the HCL OneDB™ DataBlade® API Programmer's Guide.

Return values

>=0: The new reference count for the smart large object that LO_hdl references.
MI_ERROR: The function was not successful.

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