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
Character processing
These topics describe the character-processing capabilities of the HCL® Informix® GLS library.
Other operations
In addition to the operations on characters and strings, the HCL® Informix® GLS library provides support for terminating characters and strings, allocating memory for characters and strings, and truncating and fragmenting strings.
String and character termination
You can use the HCL® Informix® GLS library with many different application programming interfaces (APIs), which might handle strings in different ways.

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.
  - Character processing
    These topics describe the character-processing capabilities of the HCL® Informix® GLS library.
    - Types of characters
      A GLS locale supports a particular code set, which maps characters to unique bit patterns called code points.
    - Character operations
      The HCL® Informix® GLS library supports character classification, case conversion, and code-set conversion operations on multibyte and wide characters.
    - String operations
      The HCL® Informix® GLS library supports string traversal and string processing operations on multibyte-character and wide-character strings.
    - Other operations
      In addition to the operations on characters and strings, the HCL® Informix® GLS library provides support for terminating characters and strings, allocating memory for characters and strings, and truncating and fragmenting strings.
      - String and character termination
        You can use the HCL® Informix® GLS library with many different application programming interfaces (APIs), which might handle strings in different ways.
        Character-string termination
        Multibyte-character termination
      - Managing memory for strings and characters
        You must make buffers large enough to hold text in any of the languages that your application will handle.
      - Keep multibyte strings consistent
        You must take special measures to perform truncation and fragmentation operations on multibyte strings so that you do not split a multibyte character.
  - 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.

String and character termination

You can use the HCL® Informix® GLS library with many different application programming interfaces (APIs), which might handle strings in different ways.

To provide flexible support for APIs, the Informix® GLS library allows you to indicate how to handle the following items:

Character-string termination
Is the string argument a null-terminated string?
Multibyte-character termination
Is the length of a multibyte character known?