Launchpad #348223: optimize catalog query by breaking out early from loop

over indexes if the result set is already empty.

doc/CHANGES.txt

@@ -27,6 +27,9 @@ Zope Changes
 
     Bugs Fixed
 
+      - Launchpad #348223: optimize catalog query by breaking out early from
+        loop over indexes if the result set is already empty.
+
       - "Permission tab": correct wrong form parameter for
         the user-permission report
 

lib/python/Products/ZCatalog/Catalog.py

+
 ##############################################################################
 #
 # Copyright (c) 2002 Zope Corporation and Contributors. All Rights Reserved.
@@ -478,7 +479,9 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
             if r is not None:
                 r, u = r
                 w, rs = weightedIntersection(rs, r)
-        
+                if not rs:
+                   break       
+
         if rs is None:
             # None of the indexes found anything to do with the request
             # We take this to mean that the query was empty (an empty filter)