This chapter provides an overview of the Siebel database upgrade process and upgrade environments, and describes the utility used to perform the upgrade. Also review topics relevant to the z/OS database upgrade in the chapters in Siebel Database Upgrade Guide that provide an overview of the upgrade process. This chapter includes the following topics:

• About Supported Siebel Upgrade Paths
• Supported Upgrade Paths for Siebel Innovation Pack 2015, Patchset 5 or Later
• Types of Siebel Database Upgrades
• Types of Siebel Database Upgrades
• About Using Oracle's Advanced Customer Services
• About Unicode Support
• About Siebel Upgrade Environments
• About the z/OS Upgrade
• About the Staging Database
• About Siebel Additive Schema Upgrade Changes
• About the Siebel Database Upgrade Process
• About the Siebel Database Configuration Utilities and Database Configuration Wizard
• About the Siebel Upgrade Wizard and Driver Files
• Job Flow of a Production Database Upgrade
• About the Override File