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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.
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®.
Opaque user-defined data types
This section describes how to use opaque user-defined data types (UDTs). This section describes the default SQLData interface and how to override the default.
Using the SQLData interface
To implement a complete UDT in Java™ code, you must supply a set of data-formatting methods that convert to and from the various representations of the data type. These methods perform input and output operations for the data type such as converting text input to the internal structure that the database server uses.
Informix® extensions to SQLInput and SQLOutput

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 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®.
    - Concepts
      This section introduces the infrastructure for creating and executing user-defined routines (UDRs) and applications that you write in Java™ to run in the HCL Informix® database server.
    - Prepare for Java™ support
      You must install and configure software before you can write user-defined routines (UDRs) in Java™ code.
    - Configuration parameters
      This section documents the configuration parameters that you need to set to use UDRs written in Java™ code. Set these parameters in the database server configuration file (the onconfig file).
    - Create Java™ user-defined routines
      A user-defined routine (UDR) is a routine that an SQL statement or another UDR can invoke. UDRs written in Java™ code use the server-side implementation of the Informix® JDBC Driver to communicate with the database server.
    - The Informix® JDBC Driver
      All UDRs written in Java™ code can access the database server data through the Informix® JDBC Driver application programming interface (API). This section briefly describes the Informix implementation of the Informix JDBC Driver API and the server-side Informix JDBC Driver.
    - Opaque user-defined data types
      This section describes how to use opaque user-defined data types (UDTs). This section describes the default SQLData interface and how to override the default.
      - Using the SQLData interface
        To implement a complete UDT in Java™ code, you must supply a set of data-formatting methods that convert to and from the various representations of the data type. These methods perform input and output operations for the data type such as converting text input to the internal structure that the database server uses.
        Default input/output routines
        Because this interface uses Java™, all the SQL I/O support functions are predefined when you register the UDT. You only need to supply the required SQLData implementation.
        SQL definitions for default I/O user-defined routines
        After you register the Java™ UDT with the database server by using the SQL procedure setUDTExtName(), you can create SQL functions and casts for it, using either the default I/O wrapper methods or explicit methods in your Java UDT class.
        Informix® extensions to SQLInput and SQLOutput
        IfmxUDTSQLInput
        IfmxUDTSQLOutput
        The circle class example
        The circle class example implements a fixed-length opaque data type.
      - Override the default I/O methods
        If the default methods are not sufficient because, for example, you want to include parentheses and other delimiting characters in the text representation, you can explicitly override the defaults with definitions of your own, after you register the Java™ UDT.
      - Limitations to streams
  - 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.

Informix® extensions to SQLInput and SQLOutput

Some of the standard SQLInput and SQLOutput Stream methods need an additional length argument to read or write an opaque data type because the Informix® JDBC Driver cannot determine the field lengths for an opaque type. Informix® database server provides the IfmxUDTSQLInput and IfmxUDTSQLOutput extensions, which inherit from the standard Informix® JDBC Driver 2.0 SQLInput and SQLOutput interfaces.