Index: branches/5.2.x/core/units/admin/admin_config.php
===================================================================
--- branches/5.2.x/core/units/admin/admin_config.php
+++ branches/5.2.x/core/units/admin/admin_config.php
@@ -30,6 +30,7 @@
 
 	'ScheduledTasks' => Array (
 		'optimize_performance' => Array ('EventName' => 'OnOptimizePerformance', 'RunSchedule' => '0 0 * * *'),
+		'purge_expired_database_cache' => Array ('EventName' => 'OnPurgeExpiredDatabaseCacheScheduledTask', 'RunSchedule' => '0 0,12 * * *'),
 	),
 
 	'TitlePresets' => Array (
Index: branches/5.2.x/core/units/admin/admin_events_handler.php
===================================================================
--- branches/5.2.x/core/units/admin/admin_events_handler.php
+++ branches/5.2.x/core/units/admin/admin_events_handler.php
@@ -1219,6 +1219,21 @@
 			}
 		}
 	}
+
+	/**
+	 * Purges expired database cache entries.
+	 *
+	 * @param kEvent $event Event.
+	 *
+	 * @return void
+	 */
+	protected function OnPurgeExpiredDatabaseCacheScheduledTask(kEvent $event)
+	{
+		$sql = 'DELETE FROM ' . TABLE_PREFIX . 'SystemCache
+				WHERE LifeTime > 0 AND Cached + LifeTime < ' . time();
+		$this->Conn->Query($sql);
+	}
+
 }