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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.
Database access
Execute user-defined routines
This section provides information about how to call a user-defined routine (UDR).
Call UDRs with the Fastpath interface
With the DataBlade® API Fastpath interface, DataBlade API modules can directly invoke a UDR that was registered in the database. This interface bypasses the overhead associated with invoking a UDR through an SQL statement. This interface bypasses the query optimizer and executor, which are needed for an SQL statement. You can use this interface to execute any SQL routine.
A user-allocated MI_FPARAM structure
The Fastpath look-up functions automatically allocate an MI_FPARAM structure and save a pointer to this structure in the function descriptor that they allocate. However, there are some cases in which you might want to allocate your own MI_FPARAM structure for the UDR that Fastpath executes.

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
    - Database access
      - Connection handling
        This section describes how to initialize, establish, and close connections.
      - Execute SQL statements
        One basic task of a DataBlade® API module is to send SQL statements to the database server for execution.
      - Execute user-defined routines
        This section provides information about how to call a user-defined routine (UDR).
        Access MI_FPARAM routine-state information
        When the routine manager calls a UDR, it passes the routine-state information as an extra argument, called the function-parameter structure, to the routine. This function-parameter structure, MI_FPARAM, holds the routine-state information for the C UDR with which it is associated.
        Call UDRs within a DataBlade® API module
        Call UDRs with the Fastpath interface
        With the DataBlade® API Fastpath interface, DataBlade API modules can directly invoke a UDR that was registered in the database. This interface bypasses the overhead associated with invoking a UDR through an SQL statement. This interface bypasses the query optimizer and executor, which are needed for an SQL statement. You can use this interface to execute any SQL routine.
        Obtain a function descriptor
        A function descriptor, MI_FUNC_DESC, contains static information about a UDR that is to be invoked with the Fastpath interface. It is basically a structured version of the row in the sysprocedures system catalog table that describes the UDR. The function descriptor also identifies the routine sequence for the associated UDR.
        Obtain information from a function descriptor
        Execute the routine
        The mi_routine_exec() function can execute any UDR that is registered in the open database. Therefore, any UDR that you can use in an SQL statement, you can directly execute with mi_routine_exec().
        A user-allocated MI_FPARAM structure
        The Fastpath look-up functions automatically allocate an MI_FPARAM structure and save a pointer to this structure in the function descriptor that they allocate. However, there are some cases in which you might want to allocate your own MI_FPARAM structure for the UDR that Fastpath executes.
        Create a user-allocated MI_FPARAM structure
        A user-allocated MI_FPARAM structure (Server)
        For C UDRs, one of the primary uses of a user-allocated MI_FPARAM structure is for data type control for generic routines. If you are calling a generic UDR, one that handles many possible data types, you can set the arguments in the MI_FPARAM structure to the specific data type.
        Pass a user-allocated MI_FPARAM structure
        To pass the user-allocated MI_FPARAM structure to the Fastpath interface, specify it as the last argument of the argument list that you provide to mi_routine_exec().
        Free a user-allocated MI_FPARAM
        The database server automatically deallocates memory for the MI_FPARAM structures that it allocates for the function descriptor of a UDR. However, the database server does not deallocate any MI_FPARAM structure that you allocate. A user-defined MI_FPARAM structure has a memory duration of PER_COMMAND.
        Release routine resources
        Obtain trigger execution information and HDR database server status
      - Exceptions and events
        This section describes exceptions and events, and explains how to handle them in DataBlade® API modules.
      - XA-compliant external data sources
    - 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.

A user-allocated MI_FPARAM structure

The Fastpath look-up functions automatically allocate an MI_FPARAM structure and save a pointer to this structure in the function descriptor that they allocate. However, there are some cases in which you might want to allocate your own MI_FPARAM structure for the UDR that Fastpath executes.

For a list of Fastpath look-up functions, see Fastpath look-up functions.

The following DataBlade® API functions support use of a user-allocated MI_FPARAM structure.


DataBlade® API function	Description
mi_fparam_allocate()	Allocates a new MI_FPARAM structure
mi_fparam_copy()	Copies an existing MI_FPARAM structure into a new MI_FPARAM structure
mi_fparam_free()	Frees a user-allocated MI_FPARAM structure
mi_fp_usr_fparam()	Determines whether a specified MI_FPARAM structure was allocated by the database server or by a UDR