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_lo_truncate() functionThe mi_lo_truncate() function truncates a smart large object at a specified byte position.

The mi_lo_truncate() function

The mi_lo_truncate() function truncates a smart large object at a specified byte position.

Syntax

mi_integer mi_lo_truncate(conn, LO_fd, offset)
   MI_CONNECTION *conn;
   MI_LO_FD LO_fd;
   mi_int8 *offset;

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_fd

An LO file descriptor for the open smart large object whose value you want to truncate.

offset

A pointer to the eight-byte integer (mi_int8) that identifies the offset at which the truncation of the smart large object begins.


Valid in client LIBMI application?	Valid in user-defined routine?
Yes	Yes

Usage

The mi_lo_truncate() function sets the last valid byte of a smart large object to the specified offset value. If this offset value is less than the current end of the smart large object, the database server reclaims all storage, from the position that offset indicates to the end of the smart large object.

Server only: The mi_lo_truncate() 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

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