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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_unlock() functionThe mi_lo_unlock() releases a byte-range lock on a smart large object.

The mi_lo_unlock() function

The mi_lo_unlock() releases a byte-range lock on a smart large object.

Syntax

mi_integer mi_lo_unlock(conn, LO_fd, offset, whence, nbytes)
   MI_CONNECTION *conn;
   MI_LO_FD LO_fd;
   mi_int8 *offset;
   mi_integer whence;
   mi_int8 *nbytes;

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 bytes you want to unlock.

offset

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

whence

An integer value that identifies the starting LO seek position.

nbytes

A pointer to the eight-byte integer (mi_int8) that specifies the number of bytes to unlock. This value cannot exceed 2 GB.


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

Usage

The mi_lo_unlock() function removes a byte-range lock on the open smart large object that LO_fd indicates. This unlock request applies to nbytes number of bytes beginning at the LO seek location that the whence and offset arguments specify.

When the mi_lo_unlock() function requests the release of a byte-range lock, the database server attempts to unlock a locked smart large object if it has a share-mode or update-mode lock. For exclusive locks, the database server does not permit the release of the lock until the end of the transaction.

Server only: The mi_lo_unlock() 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.

For more information about locks for smart large objects or on how to use byte-range locks, see the HCL OneDB DataBlade API Programmer's Guide.

Return values

MI_OK: The function was successful; the requested lock was successfully released.
MI_ERROR: The function was not successful; the requested lock cannot be released or the smart large object has not been opened for byte-range locking.