diff --git a/src/json_reverse_index.py b/src/json_reverse_index.py
index 2a899c7..5cad9d9 100755
--- a/src/json_reverse_index.py
+++ b/src/json_reverse_index.py
@@ -14,31 +14,53 @@ def load_index_json(file_path):
     if mylib.file_exists(file_path):
         json = mylib.json_read(file_path)
     else:
-        json = dict({'pardom': dict(), 'subdom': dict()})
+        json = dict({'bundle': [], 'pardom': dict(), 'subdom': dict()})
     return json
 
 
-def delete_from_index(index, bundle_ids):
+def delete_from_index(index, bundle_ids, deleteOnly=False):
+    ids_to_delete = set()
+    for bid in bundle_ids:
+        try:
+            i = index['bundle'].index(bid)
+        except ValueError:  # index not found
+            continue
+        ids_to_delete.add(i)
+        if deleteOnly:
+            index['bundle'][i] = '_'
+
+    if len(ids_to_delete) == 0:
+        return False
+
     for key in ['pardom', 'subdom']:
         for domain in list(index[key].keys()):
-            for bid in bundle_ids:
+            for i in ids_to_delete:
                 try:
-                    index[key][domain].remove(bid)
-                except ValueError:
-                    pass  # ignore if not present
+                    index[key][domain].remove(i)
+                except ValueError:  # ignore if not present
+                    continue
             if not index[key][domain]:
                 del(index[key][domain])
+    return True
 
 
 def insert_in_index(index, bundle_ids):
+    has_changes = False
     for bid in bundle_ids:
+        try:
+            i = index['bundle'].index(bid)
+        except ValueError:  # index not found
+            i = len(index['bundle'])
+            index['bundle'].append(bid)
         json, _ = mylib.json_read_evaluated(bid)
         for key in ['pardom', 'subdom']:  # assuming keys are identical
             for domain, _, _ in json[key]:
                 try:
-                    index[key][domain].append(bid)
+                    index[key][domain].append(i)
                 except KeyError:
-                    index[key][domain] = [bid]
+                    index[key][domain] = [i]
+                has_changes = True
+    return has_changes
 
 
 def process(bundle_ids, deleteOnly=False):
@@ -50,11 +72,14 @@ def process(bundle_ids, deleteOnly=False):
     # load previous index
     json = load_index_json(index_file)
     # delete previous index entries
-    delete_from_index(json, bundle_ids)
+    did_change = delete_from_index(json, bundle_ids, deleteOnly=deleteOnly)
     # write new index to disk
     if not deleteOnly:
-        insert_in_index(json, bundle_ids)
-    mylib.json_write(index_file, json, pretty=False)
+        did_change |= insert_in_index(json, bundle_ids)
+    if did_change:
+        mylib.json_write(index_file, json, pretty=False)
+    else:
+        print('  no change')
     print('')
 
 
@@ -63,5 +88,5 @@ if __name__ == '__main__':
     if len(args) > 0:
         process(args)
     else:
-        # process(['*'])
+        # process(['*'], deleteOnly=False)
         mylib.usage(__file__, '[bundle_id] [...]')