I am new to the postgres db platform and 8.5 

I noticed the following tables created as part of the db install script.  I had the custom data schema defines but I thought it would be empty but the following tables were created. (p_addess, p_contact, p_contactcontactrel, p_contactorgrel, p_organization, p_orgorrel and p_role) 

What are these tables used for? 

I am looking for information to determine if I should redo the db install and remove the custom data schema.

Thanks