Home
Extending Informix®
Beyond standard relational database objects, HCL Informix® can be extended to handle specialized data types, access methods, routines, and other objects. Informix includes many built-in extensions that are fully integrated in the database server. Informix 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 Informix.
Creating extensions
You 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 Informix® databases.
DataBlade® API Programmer's Guide
The Informix® DataBlade® API Programmer's Guide describes information about the DataBlade API, the C-language application programming interface (API) provided with HCL Informix.
Data manipulation
Smart large objects
Convert a smart large object to a file or buffer
The DataBlade® API provides support for the conversion of a smart large object to or from either an operating-system file or a user-defined buffer.
Operating-system files
The DataBlade® API supports the functions for conversion between operating-system files and smart large objects.

Extending Informix®
Beyond standard relational database objects, HCL Informix® can be extended to handle specialized data types, access methods, routines, and other objects. Informix includes many built-in extensions that are fully integrated in the database server. Informix 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 Informix.
- Informix® extensions and DataBlade® modules
  These topics describe how to use built-in database extensions and separately installed DataBlade® modules.
- Creating extensions
  You 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 Informix® databases.
  - DataBlade® API Programmer's Guide
    The Informix® DataBlade® API Programmer's Guide describes information about the DataBlade API, the C-language application programming interface (API) provided with HCL Informix.
    - DataBlade® API overview
    - Data manipulation
      - Numeric data types
        This section describes these numeric data types and the functions that the DataBlade® API supports to process numeric data.
      - Date and time data types
        This section describes the date and time data types and the functions that the DataBlade® API supports to process date and time data.
      - Complex data types
        This section describes the complex data types and the functions that the DataBlade® API supports to process collection and row-type data.
      - Smart large objects
        Smart large objects
        Storing a smart large object in a database
        To store a smart large object in a database, you must save its LO handle in a column. This section describes the valid data types to hold an LO handle and how to access a smart large object.
        The smart-large-object interface
        The smart-large-object interface contains a set of functions and data types to provide access to smart large objects.
        Creating a smart large object
        Accessing a smart large object
        Modify a smart large object
        After you have an LO file descriptor for an open smart large object, you can modify the smart large object by updating the smart large object or by altering some storage characteristics of the smart large object.
        Obtaining status information for a smart large object
        Delete a smart large object
        Convert a smart large object to a file or buffer
        The DataBlade® API provides support for the conversion of a smart large object to or from either an operating-system file or a user-defined buffer.
        Operating-system files
        The DataBlade® API supports the functions for conversion between operating-system files and smart large objects.
        User-defined buffers
        The DataBlade® API supports the functions for conversion between user-defined buffers and smart large objects.
        Convert an LO handle between binary and text
        The DataBlade® API library provides functions that convert between the binary (internal) representation of an LO handle and its text (string) representation.
        Transfer an LO handle between computers (Server)
        For an LO handle to be portable when transferred across different computer architectures, the DataBlade® API provides functions to handle type alignment and byte order.
        Using byte-range locking
        By default, the database server uses whole lock-all locks when it needs to lock a smart large object. Lock-all locks are an all or nothing lock; that is, they lock the entire smart large object.
        Pass a NULL connection (Server)
        Many functions in the smart-large-object interface take a connection descriptor as a parameter. However, many of the functions also accept a NULL-valued pointer as a connection descriptor.
    - Database access
    - Create user-defined routines
    - Appendix
      This section contains additional reference information.
  - DataBlade® API Function Reference
    The Informix® DataBlade® API Function Reference describes the DataBlade API functions and the subset of Informix ESQL/C functions that the DataBlade API supports.
  - DataBlade® Developers Kit
    The DataBlade® Developers Kit (DBDK) guides contain information about the tools you can use to develop and package DataBlade modules, which extend the functionality of HCL Informix® databases.
  - J/Foundation Developer's Guide
    The J/Foundation Developer's Guide describes how to write user-defined routines (UDRs) in the Java™ programming language for Informix®.
  - R-Tree Index User's Guide
    The Informix® R-Tree Index User's Guide describes the HCL Informix R-tree secondary access method and how to access and use its components.
  - User-Defined Routines and Data Types Developer's Guide
    The Informix® User-Defined Routines and Data Types Developer's Guide describes how to define new data types and enable user-defined routines (UDRs) to extend HCL Informix.
  - Virtual-Table Interface Guide
    The Informix® Virtual-Table Interface Programmer's Guide explains how to create a primary access method with the Virtual-Table Interface (VTI) so that users have a single SQL interface to HCL Informix tables and to data that does not conform to the storage scheme of HCL Informix.
  - Virtual-Index Interface Guide
    The Informix® Virtual-Index Interface Programmer's Guide explains how to create a secondary access method with the Virtual-Index Interface (VII) to extend the built-in indexing schemes of HCL Informix typically with a DataBlade® module.

Operating-system files

The DataBlade® API supports the functions for conversion between operating-system files and smart large objects.

Table 1. DataBlade® API functions for conversion between operating-system files and smart large objects
DataBlade® API function	Description
mi_lo_from_file(), mi_lo_from_file_by_lofd()	Copies data in an operating-system file to a smart large object
mi_lo_to_file(), mi_lo_filename()	Copies data in a smart large object to an operating-system file

The file functions have a set of file-mode constants that are distinct from the open modes of smart large objects, as the following table shows.

Table 2. File modes for operating-system files
File mode for operating-system files	Purpose
MI_O_EXCL	Fail if the file already exists
MI_O_APPEND	Append to the end of file
MI_O_TRUNC	Truncate to zero if file exists
MI_O_RDWR	Read/write mode (default)
MI_O_RDONLY	Read-only mode (copying from operating-system files only)
MI_O_WRONLY	Write-only mode (copying to operating-system files only)
MI_O_TEXT	Text mode (default off)
MI_O_CLIENT_FILE	Indication that file is on client computer (default)
MI_O_SERVER_FILE	Indication that file is on server computer

You can include an environment variable in the file name path for the mi_lo_to_file(), mi_lo_from_file(), and mi_lo_from_file_by_lofd() functions. This environment variable must be set in the server environment; that is, it must be set before the database server starts.