Oracle provides a comprehensive set of tools for upgrading Oracle Database with minimal downtime and for migrating your applications to the new release.

Topics:

• Backing Up Oracle Database for Upgrading
  Use this procedure to back up your existing Oracle Database before you attempt an upgrade.
• Upgrading with Parallel Upgrade Utility (catctl.pl and dbupgrade Shell Command)
  This section describes how to use the Parallel Upgrade Utility (catctl.pl) to run manual upgrades using parallel processing, inclusion and exclusion lists, and other features to manage your upgrade.
• Upgrading with Oracle Database Upgrade Assistant (DBUA)
  Database Upgrade Assistant (DBUA) provides a graphical user interface to guide you through the upgrade of Oracle Database. DBUA works for CDB and non-CDB database systems.
• Upgrade Scenarios for Non-CDB Oracle Databases
  Review these topics to understand the upgrade scenarios and procedures for non-CDB Oracle Databases
• Example of Manual Upgrade of Windows Non-CDB Oracle Database 11.2.0.3
  These examples show the steps to complete preupgrade checks, upgrade, and postupgrade checks for an Oracle Database 11g release 2 (11.2.0.3) upgrade to Oracle Database 12c release 2 (12.2).
• Manual Upgrade Scenarios for Multitenant Architecture Oracle Databases
  Review these topics to understand the manual upgrade scenarios and procedures for Oracle Database deployed with multitenant architecture.
• Improvements to Data Dictionary Upgrade and Upgrade Status Displays
  Oracle Database 12c includes improvements to the upgrade process, and to how upgrade status appears for the upgraded database.
• About Dbupgrade Scripts and catupgrd.sql in Earlier Releases of Oracle Database
  The function of the catupgrd.sql script is replaced by the Parallel Upgrade Utility, catctl.pl, and the dbupgrade and dbupgrade.cmd scripts.
• About Transporting and Upgrading a Database (Full Transportable Export/Import)
  You can use file-based or nonfile-based modes for transporting data.
• About Log File Location and DIAGNOSTIC_DEST
  The location of the Automatic Diagnostic Repository (ADR) and the diagnostic log files created by the upgrade scripts can vary, depending on your environment variables and parameter settings.
• Troubleshooting the Upgrade for Oracle Database
  Use these troubleshooting tips to address errors or issues that you may encounter while upgrading your database.
• Rerunning Upgrades for Oracle Database
  Use these options to rerun upgrades.
• Restarting the Upgrade from a Specific Phase that Failed Using -p
  Use this option to complete an upgrade after fixing errors.