1 Introduction to Upgrading Oracle Database
Oracle provides upgrade options and strategies that are designed for your database environment, and an array of tools that automate the Oracle Database upgrade process.
- Oracle Database Releases That Support Direct Upgrade
 Review the supported options for direct upgrades to Oracle Database 21c.
- Overview of Oracle Database Upgrade Tools and Processes
 Review these topics to understand Oracle Database terms, tools and processes.
- Major Steps in the Upgrade Process for Oracle Database
 Oracle Database upgrades consist of six major steps.
- Compatibility and Interoperability Between Oracle Database Releases
 Learn how to understand and avoid compatibility and interoperability issues that can occur because of differences in Oracle Database releases.
- About Running Multiple Oracle Database Releases
 To run multiple Oracle Database releases at the same time, follow Optimal Flexible Architecture (OFA) standards.
- About Converting Databases During Upgrades
 Review these topics to determine which is the best path for you to select to upgrade Oracle Databases.
- About Upgrading Platforms for a New Oracle Database Release
 Review these topics if you upgrade your operating system or hardware for a new Oracle Database release.
- About Image-Based Oracle Database Installation
 Understand image-based installation to simplify installation and configuration of Oracle Database software.