During upgrade the postgresql.conf file from a prior version is renamed to postgresql.conf_old. A new postgresql.conf file is created for 8.3. The new postgresql.conf file contains configurations to improve the performance of the Security Intelligence dashboard. Therefore, you must retain this file. In case, your customizations are not included in the new file, edit the new postgres.sql file. Both the files are at the following location: /var/opt/novell/sentinel/3rdparty/postgresql/data/