Fixed: Cleanup of unused alt titles.

src/NzbDrone.Core/Housekeeping/Housekeepers/CleanupOrphanedAlternativeTitles.cs

@@ -0,0 +1,26 @@
+using NzbDrone.Core.Datastore;
+
+namespace NzbDrone.Core.Housekeeping.Housekeepers
+{
+    public class CleanupOrphanedAlternativeTitles : IHousekeepingTask
+    {
+        private readonly IMainDatabase _database;
+
+        public CleanupOrphanedAlternativeTitles(IMainDatabase database)
+        {
+            _database = database;
+        }
+
+        public void Clean()
+        {
+            var mapper = _database.GetDataMapper();
+
+            mapper.ExecuteNonQuery(@"DELETE FROM AlternativeTitles
+                                     WHERE Id IN (
+                                     SELECT AlternativeTitles.Id FROM AlternativeTitles
+                                     LEFT OUTER JOIN Movies
+                                     ON AlternativeTitles.MovieId = Movies.Id
+                                     WHERE Movies.Id IS NULL)");
+        }
+    }
+}