About Large Object Locator

Large Object Locator is implemented through two data types and a set of functions

The Large Object Locator data types are lld_locator and lld_lob.

You use the lld_locator type to identify the access protocol for a large object and to point to its location. This type is a row type, stored as a row in the database. You can insert, select, delete, and update instances of lld_locator rows in the database using standard SQL INSERT, SELECT, DELETE, and UPDATE statements.

You can also pass an lld_locator row to various Large Object Locator functions. For example, to create, delete, or copy a large object, and to open a large object for reading or writing, you pass an lld_locator row to the appropriate Large Object Locator function. See The lld_locator data type for a detailed description of this data type.

The lld_lob type enables Large Object Locator to reference smart large objects, which are stored as BLOB or CLOB data in the database. The lld_lob type is identical to the BLOB and CLOB types except that, in addition to pointing to the data, it tracks whether the underlying smart large object contains binary or character data.

See The lld_lob data type for a complete description of this data type.

Large Object Locator provides a set of functions similar to UNIX™ I/O functions for manipulating large objects. You use the same functions regardless of how or where the underlying large object is stored.

The Large Object Locator functions can be divided into four main categories:

Basic functions: Creating, opening, closing, deleting, and reading from and writing to large objects.
Client functions: Creating, opening, and deleting client files and for copying large objects to and from client files. After you open a client file, you can use the basic functions to read from and write to the file.
Utility functions: Raising errors and converting errors to their SQL state equivalents.
Smart large object functions: Copying smart large objects to files and to other smart large objects

There are three interfaces to the Large Object Locator functions:

An API library
An ESQL/C library
An SQL interface

All Large Object Locator functions are implemented as API library functions. You can call Large Object Locator functions from user-defined routines within an application you build.

All Large Object Locator functions, except lld_error_raise(), are implemented as ESQL/C functions. You can use the Large Object Locator functions to build ESQL/C applications.

A limited set of the Large Object Locator functions are implemented as user-defined routines that you can execute within SQL statements. See SQL interface for a list of the Large Object Locator functions that you can execute directly in SQL statements.

Large Object Locator functions, describes all the Large Object Locator functions and the three interfaces in detail.