This manual is part of a series of manuals that discuss the Informix implementation of SQL. This volume and the Informix Guide to SQL: Syntax are references that you can use on a daily basis after you read the Informix Guide to SQL: Tutorial.

Important: This manual does not cover the product called INFORMIX-SQL or any other Informix application development tool.

Organization of This Manual

• This Introduction provides an overview of the manual and describes the documentation conventions used.
• Chapter 1, "System Catalog," provides details of the Informix system catalog, which is a collection of system catalog tables that describe the structure of an INFORMIX-Universal Server database. The chapter explains how to access and update statistics in the system catalog, shows the system catalog structure, and lists the name and data type for each column in each table. This chapter also includes information about Information Schema Views.
• Chapter 2, "Data Types," defines the column data types supported by Informix products, tells how to convert between different data types, and describes how to use specific values in arithmetic and relational expressions.
• Chapter 3, "Environment Variables," describes the various environment variables that you can or should set to properly use your Informix products. These variables identify your terminal, specify the location of your software, and define other parameters of your product environment.
• Appendix A describes the structure and contents of the stores7 demonstration database that is installed with the Informix database server products. It includes a map of the nine tables in the database, illustrates the columns on which they are joined, and displays the data in them.
• A glossary of object-relational database terms follows the chapters.
• The Index is a combined index for the manuals in the SQL series. Each page reference in the index ends with a code that identifies the manual in which the page appears. The same index also appears in the Informix Guide to SQL: Syntax and the Informix Guide to SQL: Tutorial.

Software Dependencies

• INFORMIX-Universal Server, Version 9.1

In this manual, all instances of Universal Server refer to INFORMIX-Universal Server.

• An Informix SQL application programming interface (API), such as INFORMIX-ESQL/C, Version 9.1, or the DB-Access database access utility, which is shipped as part of your database server.

Assumptions About Your Locale

This manual assumes that you use the default locale, en_us.8859-1. This locale supports U.S. English format conventions for dates, times, and currency. In addition, this locale supports the ISO 8859-1 code set, which includes the ASCII code set plus many 8-bit characters such as é, è, and ñ.

If you plan to use nondefault characters in your data or your SQL identifiers, or if you want to conform to the nondefault collation rules of character data, you need to specify the appropriate nondefault locale(s). For instructions on how to specify a nondefault locale, additional syntax, and other considerations related to GLS locales, see the Guide to GLS Functionality.

Demonstration Database

Many examples in Informix manuals are based on the stores7 demonstration database. The stores7 database is described in detail and its contents are listed in Appendix A.

The script that you use to install the demonstration database is called dbaccessdemo7 and is located in the $INFORMIXDIR/bin directory. For a complete explanation of how to create and populate the demonstration database on your database server, refer to the DB-Access User Manual.