Welcome
Client APIs and tools
You can use the HCL Informix® implementation of client APIs to develop applications for Informix database servers.
Informix GLS API
Using Informix® GLS
The HCL® Informix® GLS library enables a program to access the culture-specific information in the GLS locales that Informix provides.
Using Informix® GLS in a C-language program
Allocate memory
If the HCL® Informix® GLS function allocates memory, this memory is only allocated within the function itself and is freed before the function returns.

HCL Informix® V15.0 documentation
Welcome to the documentation for HCL Informix® 15.0 and related client tools and products.
Product overview
HCL Informix® is a fast and scalable database server that manages traditional relational, object-relational, and dimensional databases. Its small footprint and self-managing capabilities are suited to embedded data-management solutions.
Installing
These topics describe how to install HCL Informix® database servers, client products, and DataBlade® modules.
Administering
In addition to administering the database server, you can tune performance, replicate data, and archive data.
Migrating and upgrading
You can upgrade to the 15.0 release of HCL Informix® or migrate from other database servers to Informix. Upgrading is an in-place migration method that uses your existing hardware and operating system software. Some changes to the Informix database server can affect upgrading from a previous release.
Client APIs and tools
You can use the HCL Informix® implementation of client APIs to develop applications for Informix database servers.
- Change Data Capture API Programmer's Guide
- Embedded SQLJ for HCL Informix®
- ESQL/C Guide
- GLS User's Guide
  These topics describe the Global Language Support (GLS) feature available in HCL® Informix® products.
- Informix GLS API
  - Using Informix® GLS
    The HCL® Informix® GLS library enables a program to access the culture-specific information in the GLS locales that Informix provides.
    - Internationalized programs with Informix® GLS
      You can make HCL Informix® database applications easily adaptable to any culture and language.
    - Using Informix® GLS in a C-language program
      - Compile and link Informix® GLS
      - Initialize the Informix® GLS library
        Before you can use HCL® Informix® GLS functions in your application, these functions must be able to access the current processing locale.
      - Informix® GLS exceptions
        Many of the HCL® Informix® GLS functions return a unique value if they encounter an error. To further identify the cause of the error, you can use the ifx_gl_lc_errno() function to obtain the value of the Informix GLS error number.
      - Allocate memory
        If the HCL® Informix® GLS function allocates memory, this memory is only allocated within the function itself and is freed before the function returns.
      - Input and output streams
      - Run the program
    - Improve program performance
  - Character processing
    These topics describe the character-processing capabilities of the HCL® Informix® GLS library.
  - Data formatting
    You must handle the format of locale-specific data in your applications.
  - Informix® GLS functions
    These topics describe the functions that the HCL® Informix® GLS library provides. First is a summary of functions by categories. The rest of the topics provide reference information about the Informix GLS public functions, in alphabetical order.
  - Appendix
- Informix® Object Interface for C++ Guide
- Informix® ODBC Driver Guide
- Informix .NET Core Provider
  Starting with CSDK 4.50.xC4, Informix .NET Core Provider built with .NET Core SDK/Runtime v3.1 is shipped for Windows x64 and Linux x86_64 platforms.
- Informix® .NET EF Core Provider Guide
- Informix 4GL/SQL
  These topics include information about HCL Informix®4GL and SQL.
- AI and Agent Connectivity
  The Actian MCP (Model Context Protocol) server provides a standardized interface to connect Large Language Model (LLM) agents and AI applications directly to your HCL Informix database.
- Informix® JDBC Driver Guide
- Informix International Language Supplement (ILS) User Guide
  These topics include information about the translated user interface files for Informix® UNIX™ products, locales, and code set conversion tables
- Informix® OLE DB Provider Guide
Embedding Informix®
When you embed HCL Informix®, you can use enterprise-class high-availability and high performance with embeddability features such as easy programmability, a small disk and memory footprint, and silent deployment.
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.
Data warehousing
In addition to designing and implementing Informix® dimensional databases, you can use tools to create data warehouse applications and optimize your data warehouse queries.
Designing databases
The first step in creating a relational database is to construct a data model, which is a precise, complete definition of the data you want to store. After you prepare your data model, you must implement it as a database and tables. To implement your data model, you first select a data type for each column and then you create a database and tables and populate the tables with data. You can also implement fragmentation strategies and control access to your data.
JSON compatibility
You can use the popular JSON-oriented query language created by MongoDB to interact with data stored in HCL Informix®.
Security
You can secure your Informix® database server and the data that is stored in your Informix databases. You can encrypt data, secure connections, control user privileges and access, and audit data security.
SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
Troubleshooting HCL Informix®
Several troubleshooting techniques, tools, and resources are available for resolving problems that you encounter in your HCL Informix® database server environment.

Allocate memory

If the HCL® Informix® GLS function allocates memory, this memory is only allocated within the function itself and is freed before the function returns.

No Informix® GLS library function allocates memory that remains after the function returns. Therefore, you must allocate any memory for data that the Informix® GLS function needs or returns.

DataBlade® UDRs can assume that the Informix® GLS functions allocate memory with a PER_ROUTINE memory duration.

You must ensure that memory is allocated for any return value or argument that the Informix® GLS function provides to the calling program.

Tip: You must also handle memory allocation for multibyte-character and wide-character strings that the Informix® GLS functions use.