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/19.0.0/dbhome_1
$ cd $ORACLE_HOME/bin
$ ./orabaseconfig

For example:

$ ./orabaseconfig
/u01/app/oracle

Where, /u01/app/oracle is ORACLE_BASE.