Welcome
SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
Guide to SQL: Reference
The HCL® Informix® Guide to SQL: Reference contains the reference information for the system catalog tables, data types, and environment variables of the HCL Informix dialect of the SQL language, as implemented in HCL Informix. These topics also include information about the stores_demo, sales_demo, and superstore_demo databases that are included with HCL Informix.
System catalog tables
The system catalog consists of tables and views that describe the structure of the database. Sometimes called the data dictionary, these table objects contain everything that the database knows about itself. Each system catalog table contains information about specific elements in the database. Each database has its own system catalog.
SYSXTDDESC

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.
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.
- Guide to SQL: Syntax
  The HCL® Informix® Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the Informix dialect of the SQL language.
- Guide to SQL: Reference
  The HCL® Informix® Guide to SQL: Reference contains the reference information for the system catalog tables, data types, and environment variables of the HCL Informix dialect of the SQL language, as implemented in HCL Informix. These topics also include information about the stores_demo, sales_demo, and superstore_demo databases that are included with HCL Informix.
  - System catalog tables
    The system catalog consists of tables and views that describe the structure of the database. Sometimes called the data dictionary, these table objects contain everything that the database knows about itself. Each system catalog table contains information about specific elements in the database. Each database has its own system catalog.
    - Objects that the system catalog tables track
    - Using the system catalog
    - Structure of the System Catalog
    - SYSAGGREGATES
    - SYSAMS
      The sysams system catalog table contains information that is required for using built-in access methods and those created by the CREATE ACCESS_METHOD statement of SQL.
    - SYSATTRTYPES
    - SYSAUTOLOCATE
      The sysautolocate system catalog table indicates which dbspaces are available for automatic table fragmentation.
    - SYSBLOBS
    - SYSCASTS
    - SYSCHECKS
    - SYSCHECKUDRDEP
    - SYSCOLATTRIBS
      The syscolattribs system catalog table describes the characteristics of smart large objects, namely CLOB and BLOB data types.
    - SYSCOLAUTH
    - SYSCOLDEPEND
    - SYSCOLUMNS
      The syscolumns system catalog table describes each column in the database.
    - SYSCONSTRAINTS
    - SYSDEFAULTS
      The sysdefaults system catalog table lists the user-defined defaults that are placed on each column in the database. One row exists for each user-defined default value.
    - SYSDEPEND
    - SYSDIRECTIVES
    - SYSDISTRIB
      The sysdistrib system catalog table stores data-distribution information for the query optimizer to use. Data distributions provide detailed table and column information to the optimizer to improve the choice of execution paths of SELECT statements.
    - SYSDOMAINS
    - SYSERRORS
    - SYSEXTCOLS (IDS)
    - SYSEXTDFILES (IDS)
    - SYSEXTERNAL (IDS)
    - SYSFRAGAUTH
    - sysfragdist system catalog table System catalogssysfragdistSYSFRAGDIST
    - SYSFRAGMENTS
      The sysfragments system catalog table stores fragmentation information and LOW mode statistical distributions for individual fragments of tables and indexes. One row exists for each table fragment or index fragment.
    - SYSINDEXES
      The sysindexes table is a view on the sysindices table. It contains one row for each index in the database.
    - SYSINDICES
      The sysindices system catalog table describes the indexes in the database. It stores LOW mode statistics for all indexes, and contains one row for each index that is defined in the database.
    - SYSINHERITS
    - SYSLANGAUTH
    - SYSLOGMAP
    - SYSOBJSTATE
    - SYSOPCLASSES
    - sysopclstr system catalog table System catalogssysopclstrSYSOPCLSTR
    - SYSPROCAUTH
    - SYSPROCBODY
    - SYSPROCCOLUMNS
    - SYSPROCEDURES
      The sysprocedures system catalog table lists the characteristics for each function and procedure that is registered in the database. It contains one row for each routine.
    - SYSPROCPLAN
    - SYSREFERENCES
    - SYSROLEAUTH
    - SYSROUTINELANGS
    - SYSSECLABELAUTH
    - SYSSECLABELCOMPONENTS
    - SYSSECLABELCOMPONENTELEMENTS
    - SYSSECLABELNAMES
    - SYSSECLABELS
    - SYSSECPOLICIES
    - SYSSECPOLICYCOMPONENTS
    - SYSSECPOLICYEXEMPTIONS
    - SYSSEQUENCES
    - SYSSURROGATEAUTH
      The syssurrogateauth system catalog table stores trusted user and surrogate user information.
    - SYSSYNONYMS
    - SYSSYNTABLE
    - SYSTABAMDATA
    - SYSTABAUTH
    - systables system catalog table System catalogssystablesSYSTABLES
    - SYSTRACECLASSES
    - SYSTRACEMSGS
      The systracemsgs system catalog table stores internationalized trace messages that you can use in debugging user-defined routines.
    - SYSTRIGBODY
    - SYSTRIGGERS
    - SYSUSERS
      The sysusers system catalog table lists the authorization identifier of every individual user, or public for the PUBLIC group, who holds database-level access privileges. This table also lists the name of every role that holds access privileges on any object in the database.
    - SYSVIEWS
    - SYSVIOLATIONS
      The sysviolations system catalog table stores information about constraint violations for base tables.
    - SYSXADATASOURCES
      The sysxadatasources system catalog table stores XA data sources.
    - SYSXASOURCETYPES
      The sysxasourcetypes system catalog table stores XA data source types.
    - SYSXTDDESC
    - SYSXTDTYPEAUTH
      The sysxtdtypeauth system catalog table identifies the privileges on each UDT (user-defined data type).
    - SYSXTDTYPES
      The sysxtdtypes system catalog table has an entry for each UDT (user-defined data type), including opaque and distinct data types and complex data types (named ROW types, unnamed ROW types, and COLLECTION types), that is defined in the database.
    - Information Schema
  - Data types
    Every column in a table in a database is assigned a data type. The data type precisely defines the kinds of values that you can store in that column.
  - Environment variables
    Various environment variables affect the functionality of your HCL Informix® products. You can set environment variables that identify your terminal, specify the location of your software and define other parameters.
  - Appendixes
- Guide to SQL: Tutorial
  The HCL® Informix® Guide to SQL: Tutorial shows how to use basic and advanced structured query language (SQL) to access and manipulate the data in your databases. It discusses the data manipulation language (DML) statements as well as triggers and stored procedure language (SPL) routines, which DML statements often use.
Troubleshooting HCL Informix®
Several troubleshooting techniques, tools, and resources are available for resolving problems that you encounter in your HCL Informix® database server environment.

SYSXTDDESC

The sysxtddesc system catalog table provides a text description of each user-defined data type (UDT) defined in the database. The sysxtddesc table has the following columns.


Column	Type	Explanation
extended_id	INTEGER	Code uniquely identifying the extended data types
seqno	SMALLINT	Value to order and identify one line of the description of the UDT A new line is created only if the remaining text string is larger than 255 bytes.
description	CHAR(256)	Textual description of the extended data type

A composite index on extended_id and seqno allows duplicate values.