Organization of This Manual

• This Introduction provides an overview of the manual and describes the documentation conventions used.
• Chapter 1, "Extending Data Types," introduces the concept of a data type and describes how you can extend data types with Universal Server.
• Chapter 2, "Extending an Operation," describes how you can extend the operations that are available on a data type.
• Chapter 3, "Creating User-Defined Casts," describes how to create a casting function for a data type.
• Chapter 4, "Extending an Operator Class," describes how you can extend an operator class to provide additional functionality for a secondary access method (an index).
• Chapter 5, "Creating an Opaque Data Type," provides the steps for the creation of an opaque data type, a user-defined data type for which you must provide both the internal structure and the functions that operate on this structure.
• Chapter 6, "Writing Support Functions," describes the support functions for an opaque data type and what capabilities they provide for the opaque type.

Software Dependencies

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

Assumptions About Your Locale

This manual assumes that you are using 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 of the Informix Guide to SQL: Reference.

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.