Welcome
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.
Informix® extensions and modules
These topics describe how to use built-in database extensions and separately installed modules.
Performing XML Publishing
The IBM® Informix® XML User's Guide includes information about using built-in functions for XML publishing with HCL Informix.
Publishing SQL result sets in XML
Several functions let you publish XML from SQL queries.
Special characters in XML functions
The XML functions of the database server automatically handle special characters.

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.
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.
- Informix® extensions and modules
  These topics describe how to use built-in database extensions and separately installed modules.
  - Database Extensions User's Guide
    The IBM® Informix® Database Extensions User's Guide explains how to use the database extensions that come with HCL Informix: Large Object Locator, MQ messaging, binary data types, basic text search, node data type, and SQL packages.
  - Performing XML Publishing
    The IBM® Informix® XML User's Guide includes information about using built-in functions for XML publishing with HCL Informix.
    - Publishing SQL result sets in XML
      Several functions let you publish XML from SQL queries.
      - XML publishing
        XML publishing provides a way to transform results of SQL queries into XML structures.
      - The idsxmlvp virtual processor class
        The XML functions that HCL® Informix® provides run in a virtual processor class named idsxmlvp.
      - Special characters in XML functions
        The XML functions of the database server automatically handle special characters.
      - The extract() and extractclob() XML functions
        Evaluates an XPATH expression on an XML column, document, or string. These functions are identical except that extractclob() returns a CLOB instead of LVARCHAR.
      - The existsnode() XML function
        Determines whether the XPath evaluation results in at least one XML element.
      - The extractvalue() and extractvalueclob() XML functions
        Returns the value of the XML node in contrast to extract(), which returns the XML node.
      - The genxml() and genxmlclob() XML functions
        Return rows of SQL results as XML elements. Use genxmlclob if the returned row is greater than LVARCHAR(32739).
      - The genxmlelem() and genxmlelemclob() XML functions
      - The genxmlqueryhdr() and genxmlqueryhdrclob() XML functions
        Returns the result set of a query in XML with the XML header.
      - The genxmlquery() and genxmlqueryclob() XML functions
        These functions take a SQL query as a parameter and return the result set in XML.
      - The genxmlschema() and genxmlschemaclob() XML functions
        These functions generate an XML schema and result in XML format.
      - The idsxmlparse() XML function
        Parse an XML document or fragment to determine whether it is well formed.
    - Transforming documents with XSLT functions
      Apply XSL stylesheets and transforms to XML documents.
  - Spatial Data User's Guide
    The contains information to assist you in using the HCL® Informix® spatial extension. The HCL Informix spatial extension adds custom data types and supporting routines to the server.
  - TimeSeries Data User's Guide
    The IBM® Informix® TimeSeries Data User's Guide contains information to assist you in using the TimeSeries extension with HCL Informix.
  - Spatiotemporal Search for Moving Objects User's Guide
    The describes how to program applications to search data from moving objects in HCL Informix® databases using the spatiotemporal search extension.
- 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.
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.

Special characters in XML functions

The XML functions of the database server automatically handle special characters.

When a SQL result set contains special characters, the XML function will automatically handle it. These special characters are listed in the following table.

Table 1. Special characters handled by XML functions
Character	Resolved in XML as
Less than (<)	<
Greater than (>)	>
Double quote (")	"
Apostrophe (ˋ)	'
Ampersand (&)	&