Index: openacs-4/packages/acs-kernel/sql/oracle/acs-relationships-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/oracle/acs-relationships-create.sql,v
diff -u -r1.13 -r1.14
--- openacs-4/packages/acs-kernel/sql/oracle/acs-relationships-create.sql	5 Jan 2010 15:30:26 -0000	1.13
+++ openacs-4/packages/acs-kernel/sql/oracle/acs-relationships-create.sql	6 Jan 2010 20:07:24 -0000	1.14
@@ -355,17 +355,15 @@
 			constraint acs_data_links_obj_two_fk
 			references acs_objects (object_id)
                         on delete cascade,
-    relation_tag    varchar2(100)
+    relation_tag    varchar2(100),
+    constraint acs_data_links_un unique
+    (object_id_one, object_id_two, relation_tag)    
 );
 
 create index acs_data_links_id_one_idx on acs_data_links (object_id_one);
 create index acs_data_links_id_two_idx on acs_data_links (object_id_two);
 create index acs_data_links_rel_tag_idx on acs_data_links (relation_tag);
 
-create unique index acs_data_links_un on acs_data_links (
-  object_id_one, object_id_two, relation_tag
-);
-
 --------------
 -- TRIGGERS --
 --------------
Index: openacs-4/packages/acs-kernel/sql/oracle/upgrade/upgrade-5.6.0d3-5.6.0d4.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/oracle/upgrade/upgrade-5.6.0d3-5.6.0d4.sql,v
diff -u -r1.2 -r1.3
--- openacs-4/packages/acs-kernel/sql/oracle/upgrade/upgrade-5.6.0d3-5.6.0d4.sql	5 Jan 2010 15:30:26 -0000	1.2
+++ openacs-4/packages/acs-kernel/sql/oracle/upgrade/upgrade-5.6.0d3-5.6.0d4.sql	6 Jan 2010 20:07:24 -0000	1.3
@@ -4,6 +4,5 @@
 
 alter table acs_data_links drop constraint acs_data_links_un;
 
-create unique index acs_data_links_un on acs_data_links (
-  object_id_one, object_id_two, relation_tag
-);
\ No newline at end of file
+alter table acs_data_links add constraint acs_data_links_un unique 
+(object_id_one, object_id_two, relation_tag);
\ No newline at end of file
Index: openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql,v
diff -u -r1.29 -r1.30
--- openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql	5 Jan 2010 15:30:26 -0000	1.29
+++ openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql	6 Jan 2010 20:07:24 -0000	1.30
@@ -378,16 +378,15 @@
                         constraint acs_data_links_obj_two_fk
                         references acs_objects (object_id)
                         on delete cascade,
-        relation_tag    varchar(100)
+        relation_tag    varchar(100),
+        constraint acs_data_links_un unique
+        (object_id_one, object_id_two, relation_tag)
 );
 
 create index acs_data_links_id_one_idx on acs_data_links (object_id_one);
 create index acs_data_links_id_two_idx on acs_data_links (object_id_two);
 create index acs_data_links_rel_tag_idx on acs_data_links (relation_tag);
 
-create unique index acs_data_links_un on acs_data_links (
-  object_id_one, object_id_two, relation_tag
-);
 
 --------------
 -- TRIGGERS --
Index: openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d3-5.6.0d4.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d3-5.6.0d4.sql,v
diff -u -r1.2 -r1.3
--- openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d3-5.6.0d4.sql	5 Jan 2010 15:30:26 -0000	1.2
+++ openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d3-5.6.0d4.sql	6 Jan 2010 20:07:24 -0000	1.3
@@ -4,6 +4,5 @@
 
 alter table acs_data_links drop constraint acs_data_links_un;
 
-create unique index acs_data_links_un on acs_data_links (
-  object_id_one, object_id_two, relation_tag
-);
\ No newline at end of file
+alter table acs_data_links add constraint acs_data_links_un unique 
+(object_id_one, object_id_two, relation_tag);
\ No newline at end of file