diff --git a/src/calibre/db/cache.py b/src/calibre/db/cache.py
index a17551f623..1eb249c0b4 100644
--- a/src/calibre/db/cache.py
+++ b/src/calibre/db/cache.py
@@ -510,7 +510,7 @@ class Cache(object):
             return frozenset(self.fields[field].table.col_book_map)
 
         try:
-            return frozenset(itervalues(self.fields[field].table.id_map))
+            return frozenset(self.fields[field].table.id_map.values())
         except AttributeError:
             raise ValueError('%s is not a many-one or many-many field' % field)
 
diff --git a/src/calibre/gui2/complete2.py b/src/calibre/gui2/complete2.py
index f28232defa..9b49f6164c 100644
--- a/src/calibre/gui2/complete2.py
+++ b/src/calibre/gui2/complete2.py
@@ -36,8 +36,10 @@ class CompleteModel(QAbstractListModel):  # {{{
         self.current_prefix = ''
 
     def set_items(self, items):
-        items = [unicode_type(x).strip() if self.strip_completion_entries else unicode_type(x) for x in items]
-        items = [x for x in items if x]
+        if self.strip_completion_entries:
+            items = (str(x).strip() for x in items if x)
+        else:
+            items = (str(x) for x in items if x)
         items = tuple(sorted(items, key=self.sort_func))
         self.beginResetModel()
         self.all_items = self.current_items = items
diff --git a/src/calibre/gui2/dialogs/search.py b/src/calibre/gui2/dialogs/search.py
index 771da22b52..4638f0a059 100644
--- a/src/calibre/gui2/dialogs/search.py
+++ b/src/calibre/gui2/dialogs/search.py
@@ -127,22 +127,21 @@ def create_simple_tab(self, db):
     le.set_separator('&')
     le.set_space_before_sep(True)
     le.set_add_separator(tweaks['authors_completer_append_separator'])
-    le.update_items_cache(db.all_author_names())
+    le.update_items_cache(db.new_api.all_field_names('authors'))
     l.addRow(_('&Author:'), le)
 
     self.series_box = le = EditWithComplete(self)
     le.lineEdit().setPlaceholderText(_('The series to search for'))
     le.setObjectName('series_box')
-    all_series = sorted((x[1] for x in db.all_series()), key=sort_key)
     le.set_separator(None)
-    le.update_items_cache(all_series)
+    le.update_items_cache(db.new_api.all_field_names('series'))
     le.show_initial_value('')
     l.addRow(_('&Series:'), le)
 
     self.tags_box = le = EditWithComplete(self)
     le.setObjectName('tags_box')
     le.lineEdit().setPlaceholderText(_('The tags to search for'))
-    self.tags_box.update_items_cache(db.all_tags())
+    self.tags_box.update_items_cache(db.new_api.all_field_names('tags'))
     l.addRow(_('Ta&gs:'), le)
 
     searchables = sorted(db.field_metadata.searchable_fields(),
@@ -490,4 +489,5 @@ if __name__ == '__main__':
     app = Application([])
     d = SearchDialog(None, db)
     d.exec_()
+
     print(d.search_string())