Index: openacs-4/packages/acs-lang/sql/postgresql/message-catalog.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-lang/sql/postgresql/message-catalog.sql,v
diff -u -r1.18 -r1.18.2.1
--- openacs-4/packages/acs-lang/sql/postgresql/message-catalog.sql	7 Aug 2017 23:47:56 -0000	1.18
+++ openacs-4/packages/acs-lang/sql/postgresql/message-catalog.sql	25 Aug 2020 13:38:12 -0000	1.18.2.1
@@ -27,6 +27,14 @@
                        on delete cascade
                        constraint lang_message_keys_package_key_nn
                        not null,
+
+    -- This optional column allows to bind the message key to the
+    -- lifetime of an acs_object: upon object's deletion, the message
+    -- key will be automatically deleted from the system.
+    object_id          integer constraint lang_message_keys_object_id_fk
+                       references acs_objects(object_id)
+                       on delete cascade,
+
     description        text,
     constraint lang_message_keys_pk
     primary key (message_key, package_key)