Were synonyms added to other schemas in the database? There is a known issue with the Oracle JDBC driver when the DB user has privileges to multiple schemas and synonyms are in use. This can lead to the wrong metadata being returned.
Thank you for responding to the query posted. The issue has been now addressed with help from Pega Support team. The documentation on the instalation procedure was incorrect and the failure was happening because of access issues.
Had to provide the same privliges as admin user to base user as well for the installation to happen successfully.