Understanding Routine Resolution

You can assign the same name to different UDRs, as long as the routine signature is unique. It is the routine signature that uniquely identifies a UDR, not the routine name alone. A routine that has many versions is called an overloaded routine. When you invoke an overloaded routine, the database server must uniquely identify which routine to execute. This process of identifying the UDR to execute is called routine resolution.

This section provides the following information about routine resolution:

• What is the routine signature?
• What is an overloaded routine?
• How to you create overloaded routines?
• What is the routine-resolution process?

You need to understand the routine-resolution process to:

• Obtain the data results that you expect from a UDR.
• Avoid unintentional side effects if the wrong UDR executes.
• Understand when you need to write an overloaded routine.