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

over indexes if the result set is already empty.

doc/CHANGES.rst

@@ -35,7 +35,10 @@ Restructuring
 Bugs Fixed
 ++++++++++
 
-- Launchpad#344098: in ``skel/etc/zope.conf.ing``, replaced commented-out
+- Launchpad #348223: optimize catalog query by breaking out early from loop
+  over indexes if the result set is already empty.
+
+- Launchpad #344098: in ``skel/etc/zope.conf.ing``, replaced commented-out
   ``read-only-database`` option, which is deprecated, with pointers to the
   appropos sections of ZODB's ``component.xml``.  Updated the description
   of the ``zserver-read-only-mode`` directive to indicate its correct
@@ -187,7 +190,7 @@ Features added
 Bugs Fixed
 ++++++++++
 
-- Launchpad ##332168: Connection.py: do not expose DB connection strings
+- Launchpad #332168: Connection.py: do not expose DB connection strings
   through exceptions
 
 - Specified height/width of icons in ZMI listings so the table doesn't

src/Products/ZCatalog/Catalog.py

+
 ##############################################################################
 #
 # Copyright (c) 2002 Zope Corporation and Contributors. All Rights Reserved.
@@ -477,7 +478,9 @@ 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)