schema/postgres: fix wrong uniqueness

fixes #1762

doc/82-Changelog.md

@@ -20,6 +20,10 @@ before switching to a new version.
 * FIX: Loop detection works again (#1631)
 * FEATURE: RO users could want to see where a configured service originated (#1785)
 
+### DB Schema
+* FIX: it wasn't possible to use the same custom var in multiple notification
+  definitions on PostgreSQL (#1762)
+
 ### Icinga Configuration
 * FIX: escape newly introduced Icinga 2 keywords (#1765)
 

schema/pgsql-migrations/upgrade_158.sql

@@ -0,0 +1,6 @@
+DROP INDEX IF EXISTS notification_var_search_idx;
+CREATE INDEX notification_var_search_idx ON icinga_notification_var (varname);
+
+INSERT INTO director_schema_migration
+  (schema_version, migration_time)
+  VALUES (158, NOW());

schema/pgsql.sql

@@ -1748,10 +1748,9 @@ CREATE TABLE icinga_notification_var (
 );
 
 CREATE INDEX notification_var_command ON icinga_notification_var (notification_id);
-CREATE UNIQUE INDEX notification_var_search_idx ON icinga_notification_var (varname);
+CREATE INDEX notification_var_search_idx ON icinga_notification_var (varname);
 CREATE INDEX notification_var_checksum ON icinga_notification_var (checksum);
 
-
 CREATE TABLE icinga_notification_field (
   notification_id integer NOT NULL,
   datafield_id integer NOT NULL,
@@ -2087,4 +2086,4 @@ CREATE TABLE icinga_timeperiod_exclude (
 
 INSERT INTO director_schema_migration
   (schema_version, migration_time)
-  VALUES (157, NOW());
+  VALUES (158, NOW());