Function overview

A user-defined function (UDF) is a program that the user defines and can be called like any other system function.

You can create several types of user-defined functions:

External function:
External functions can be written in any system supported language.

SQL function:
An SQL function is defined entirely in SQL and can contain SQL statements, including SQL control statements.

Java-defined function:
A Java-defined function is defined entirely in Java. You create a Java-defined function from the External Function dialog.

Sourced function:
A sourced function is built over any built-in or existing user-defined function. It can then be altered to suit the needs of the new function. Using sourced functions gives you the ability to quickly added functionality to your user-defined types.

Additionally, you can create functions to return a single value (scalar) or to return a table of values. Table functions can be either external or SQL functions; they cannot be sourced.

For a listing of built-in functions, see Built-In Functions in the SQL Reference topic in the Information Center Link to Information center.

For more information about user-defined functions, see User-defined functions (UDF) in the SQL Programming topic in the Information Center Link to Information center.

You can perform the following tasking with functions: