Jerric and I discussed this yesterday. It's true the DUAL table doesn't come with PostgreSQL (as it does with Oracle), but it can easily be created:
create table dual as select 'X' as dummy;
The WDK install has separate Oracle- and PostgreSQL-specific SQL scripts for the install. The simplest thing would be to add the above to the PostgreSQL version, persistent_tables_postgres.sql. But, since only the template site needs that, and not the WDK itself, it would be cleaner and more correct to add an SQL script to WDKTemplateSite. I'm planning to do that, and have the install script prompt the user to run it.
Would you (or can I) run the above in the PostgreSQL instance(s) that Jenkins is using?
-- John