Home Database Oracle Oracle Database Release 20 Oracle Database 20c Install and Upgrade Database Licensing Information User Manual HTML PDF Describes Oracle Database licensing. If you have a question about your licensing needs, contact your Oracle sales representative. Database Release Notes HTML PDF Contains information about new features, changes, unsupported products, preinstallation requirements, generic and platform-specific bug fixes, and known issues that are not included in the Oracle Database Documentation Library. Database Upgrade Guide HTML PDF Guides you through the process of planning and performing upgrades for Oracle Database. This book also provides information about compatibility, upgrading applications, and changes in the new release that affect upgrading Oracle Database.