About Oracle Base Config

Both, in a read-only ORACLE_HOME and read/write ORACLE_HOME, the configuration files reside in a location known as ORACLE_BASE_CONFIG.

In a read/write ORACLE_HOME, the ORACLE_BASE_CONFIG path is the same as the ORACLE_HOME path because it is located at $ORACLE_HOME. However, in a read-only ORACLE_HOME, the ORACLE_BASE_CONFIG path is the same as ORACLE_BASE.

ORACLE_BASE_CONFIG/dbs contains the configuration files for ORACLE_HOME. Each file in the dbs directory contains $ORACLE_SID so that the directory can be shared by many different ORACLE_SIDs.

To print the ORACLE_BASE_CONFIG path, run the orabaseconfig command from the $ORACLE_HOME/bin directory:
$ setenv ORACLE_HOME /u01/app/oracle/product/23.0.0/dbhome_1
$ cd $ORACLE_HOME/bin
$ ./orabaseconfig

The orabaseconfig command returns the location of ORACLE_BASE_CONFIG irrespective of whether the home is a read-only ORACLE_HOME or a read/write ORACLE_HOME.

For example, to know the location of configuration files like SPFILE and the password file, run orabaseconfig:

Example 12-3 Output in Read-Only ORACLE_HOME

$ ./orabaseconfig
/u01/app/oracle

Where, /u01/app/oracle is the ORACLE_BASE.

Example 12-4 Output in Read/Write ORACLE_HOME

$ ./orabaseconfig
/u01/app/oracle/product/23.0.0/dbhome_1

where, /u01/app/oracle/product/23.0.0/dbhome_1 is the ORACLE_HOME.