Different versions of Oracle, have different search order for the LDAP.ORA file.
- Version 8i: TNS_ADMIN can not used. Search path order is $ORACLE_HOME/network/admin
- Version 9i: TNS_ADMIN can be used. Search path order is TNS_ADMIN if set, Then ORACLE_HOME/network/admin
- Version 10.1: TNS_ADMIN can not used. Search path order is LDAP_ADMIN if set, ORACLE_HOME/ldap/admin and then ORACLE_HOME/network/admin
- Version 10.2: TNS_ADMIN can be used. Search path order is LDAP_ADMIN if set, ORACLE_HOME/ldap/admin, TNS_ADMIN if set and then ORACLE_HOME/network/admin
- Version 11g: TNS_ADMIN can be used. Search path order is LDAP_ADMIN if set, ORACLE_HOME/ldap/admin, TNS_ADMIN if set and then ORACLE_HOME/network/admin.
In 10g and newer versions LDAP_ADMIN can be used to point to the location of the LDAP.ORA file
When created with Oracle Internet Directory Configuration Assistant, ldap.ora is located in the $ORACLE_HOME/ldap/admin directory on UNIX operating systems and the ORACLE_HOME\ldap\admin directory on Windows operating systems. When created with Oracle Net Configuration Assistant, ldap.ora is located in the $ORACLE_HOME/network/admin directory on UNIX operating systems and the ORACLE_HOME\network\admin directory on Windows operating systems. ldap.ora can also be stored in the directory specified by the LDAP_ADMIN or TNS_ADMIN environment variable.