From 722705468fa140cd4211ed17ed45f29da2a8dcf8 Mon Sep 17 00:00:00 2001
From: Raul Ochoa <rochoaf@gmail.com>
Date: Tue, 14 Jul 2015 20:53:26 +0200
Subject: [PATCH] Not adding surrogate keys for empty affected tables

---
 lib/cartodb/controllers/named_maps.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/cartodb/controllers/named_maps.js b/lib/cartodb/controllers/named_maps.js
index a0be85b7..6936332f 100644
--- a/lib/cartodb/controllers/named_maps.js
+++ b/lib/cartodb/controllers/named_maps.js
@@ -56,7 +56,9 @@ NamedMapsController.prototype.sendResponse = function(req, res, resource, header
 
                 var tablesCacheEntry = new TablesCacheEntry(dbName, result.affectedTables);
                 res.header('X-Cache-Channel', tablesCacheEntry.getCacheChannel());
-                self.surrogateKeysCache.tag(res, tablesCacheEntry);
+                if (result.affectedTables.length > 0) {
+                    self.surrogateKeysCache.tag(res, tablesCacheEntry);
+                }
             }
             self.app.sendResponse(res, [resource, 200]);
         }