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
The Informix GLS API Programmer's Guide describes the global language support (GLS) application programming interface (API) available in Informix® ESQL/C and HCL Informix modules.
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.
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.
String deallocation
The HCL® Informix® GLS library does not automatically deallocate memory that you dynamically allocate. Once you no longer need the string buffer, you must ensure that you deallocate any memory that your application has dynamically allocated for multibyte-character and wide-character strings.

HCL Informix® V15.0.0 documentation
Welcome to the documentation for HCL Informix® 15.0.0 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 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 15.0.0 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
  The HCL® Informix® Change Data Capture API Programmer's Guide describes how to program applications to process changed data from HCL Informix databases using the HCL Informix Change Data Capture API.
- Embedded SQLJ for HCL Informix®
  The HCL® Informix® Embedded SQLJ User's Guide contains information about using IBM Informix Embedded SQLJ.
- ESQL/C Guide
  The HCL® Informix® Enterprise Replication Guide explains how to use , the Informix implementation of Embedded Structured Query Language (SQL) for C (ESQL/C), to create client applications with database-management capabilities.
- GLS User's Guide
  The HCL® Informix® GLS User's Guide describes the Global Language Support (GLS) feature available in HCL Informix products.
- Informix GLS API
  The Informix GLS API Programmer's Guide describes the global language support (GLS) application programming interface (API) available in Informix® ESQL/C and HCL Informix modules.
  - 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.
      - 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.
        Multibyte-character-string allocation
        Multibyte characters have varying lengths. When you represent a multibyte-character string in an array, the number of array elements does not equal the number of multibyte characters in the string. Therefore, you cannot use the same allocation method for multibyte strings as for single-byte strings.
        Wide-character-string allocation
        When you represent a wide-character string in an array, the number of array elements does equal the number of wide characters in the string. Therefore, you can use the same allocation method for wide-character strings as for single-byte strings.
        String deallocation
        The HCL® Informix® GLS library does not automatically deallocate memory that you dynamically allocate. Once you no longer need the string buffer, you must ensure that you deallocate any memory that your application has dynamically allocated for multibyte-character and wide-character strings.
      - 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 public functions, in alphabetical order.
  - Appendix
- Informix® Object Interface for C++ Guide
  The Informix® Object Interface for C++ Programmer's Guide describes how to develop HCL Informix client applications by using the object-oriented C++ programming language.
- Informix® ODBC Driver Guide
  The Informix® ODBC Driver Programmer's Manual serves as a user guide and reference for HCL Informix ODBC Driver, which is the Informix implementation of the Microsoft™ Open Database Connectivity (ODBC) interface, Version 3.0.
- .NET provider options
  The HCL Data Server Provider for .NET IBM® DB2® provider option is the preferred Informix® provider for developing new applications.
- HCL Informix 4GL
  This topic provides a link to the Informix 4GL documentation.
- Informix® JDBC Driver Guide
  The HCL® Informix® JDBC Driver Programmer's Guide describes how to install, load, and use HCL Informix JDBC Driver to connect to the Informix database from within a Java™ application or applet.
- 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
  The HCL Informix OLE DB Provider Programmer's Guide describes the software requirements for using HCL Informix® OLE DB Provider, show how to install and configure the provider for your use, and explain how to use Informix OLE DB Provider to enable client applications, such as ActiveX Data Object (ADO) applications and web pages, to access data on the Informix server.
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 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 deallocation

The HCL® Informix® GLS library does not automatically deallocate memory that you dynamically allocate. Once you no longer need the string buffer, you must ensure that you deallocate any memory that your application has dynamically allocated for multibyte-character and wide-character strings.

The does provide some automatic garbage collection for memory that you allocate dynamically. When this memory is deallocated depends on the memory duration with which it was allocated. However, it is good programming practice to handle memory deallocation implicitly whenever possible. For more information about memory management with the , see the HCL® Informix® DataBlade® API Programmer's Guide.