Hello, To support a forum application I have a "forum" table:
Column | Type -------------+----------------------------- created_by | integer created_on | timestamp without time zone modified_by | integer modified_on | timestamp without time zone id_forum | integer id_parent | integer subject | text message | text id_show | integer id_thread | integer id_person | integer The id_show and id_person columns are meant to point to a show or person object about which the specific forum thread is started (threads can also have a "free" subject and these fields are then empty). Now I'd like to add forums about locations (theatres, museums, etc.) so I am thinking about adding an id_location column, but this method seems a bit inelegant to me: - every subsequent message of the thread will carry these useless fields (only the first message in thread uses one of them), - if I want to connect a forum to a new type of object, yet a new id_<object> will be required, Is there a better way to have a single field that can relate with several objects and still benefit from integrity checks? Thanks, ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend