System Administrator's Guide/Enabling Plpgsql
If your database has been configured without plpgsql as a trusted language, and you are installing or upgrading to Mahara 1.5, you will need to ensure the plpgsql language is available in your Mahara database.
Enable PL/pgSQL using the psql terminal client
The following commands can be used in your psql database client:
CREATE TRUSTED LANGUAGE plpgsql; GRANT USAGE ON LANGUAGE plpgsql TO <mahara_db_user>;
Replace <mahara_db_user> with the user that mahara connects to the db with.
(Tested on Red Hat Enterprise Linux 5.8, PostgreSQL 8.1.23)