Evolution of Oracle Homes

Learn about read-only Oracle home concepts like Oracle base home, Oracle base config, and orabasetab.

• About Read-Only Oracle Homes
  In Oracle Database 21c, an Oracle Database installation configures all Oracle Database homes in read-only mode by default. A read-only Oracle home does not imply that the file system and the Oracle home is in read-only mode. The file system and mount point should always be in read/write mode.
• About Oracle Base Home
  In a read-only ORACLE_HOME the user-specific files, instance-specific files, and log files reside in a location known as the ORACLE_BASE_HOME.
• About Oracle Base Config
  In a read-only ORACLE_HOME the configuration files reside in a location known as ORACLE_BASE_CONFIG.
• About orabasetab
  The orabasetab file is used to define fundamental directories based on $ORACLE_HOME, ORACLE_BASE, ORACLE_BASE_HOME and ORACLE_BASE_CONFIG.