DataBlade Module Development Overview Informix DataBlade Modules

The Informix Large Object Locator DataBlade module enables you to create a single consistent interface to smart large objects. It expands the concept of smart large objects to include data stored outside the database. Smart large object data exceeds a length of 255 bytes or contains non-ASCII characters.

With the Informix Large Object Locator DataBlade module, you create a reference to a smart large object and store the reference as a row in the database. The object itself can reside outside the database: for example, on a file system (or it could be a BLOB or CLOB column in the database). The reference identifies the type, or access protocol, of the object and points to its storage location.

The Informix Large Object Locator DataBlade module is a foundation DataBlade module for other DataBlade modules that handle smart large objects.

The Informix Large Object Locator DataBlade module provides new data types and functions to extend your database server.

The lld_locator data type is a row data type that contains the access protocol for a smart large object and a pointer to its location. The lld_lob data type is an opaque data type that is identical to the BLOB and CLOB data types, except that in addition to pointing to the data, it tracks whether the underlying smart large object contains binary or character data. It is contained in the lld_locator data type as a field in the row.

The Informix Large Object Locator DataBlade module provides basic functions for creating, opening, closing, deleting, reading from, and writing to smart large objects; client functions to process client files; utility functions for raising errors; and functions for copying smart large objects.

Most of the Informix Large Object Locator DataBlade module functions are implemented in an API library, an ESQL/C library, and an SQL interface for maximum programming flexibility.

For more information, see the Informix Large Object Locator DataBlade Module User's Guide.