diff -r 2f006b010391 -r e4f8c2479e78 app/DoctrineMigrations/Version20140129151724.php
--- a/app/DoctrineMigrations/Version20140129151724.php	Tue Feb 04 11:23:12 2014 +0100
+++ b/app/DoctrineMigrations/Version20140129151724.php	Wed Apr 02 14:35:17 2014 +0200
@@ -4,7 +4,8 @@
 
 use Doctrine\DBAL\Migrations\AbstractMigration,
     Doctrine\DBAL\Schema\Schema,
-	IRI\Bundle\WikiTagBundle\Utils\WikiTagUtils;
+	IRI\Bundle\WikiTagBundle\Utils\WikiTagUtils,
+	IRI\Bundle\WikiTagBundle\Listener\DocumentListener;
 
 /**
  * Migration for WikiTagBundle <= V00.13
@@ -26,6 +27,20 @@
         // Avoid php annoying memory leaks
         $em->getConnection()->getConfiguration()->setSQLLogger(null);
         
+        // remove event listener to avoid useless sql queries. Only WikiTag's Tags are modified
+        $listenerInst = null;
+        foreach ($em->getEventManager()->getListeners() as $event => $listeners) {
+        	foreach ($listeners as $hash => $listener) {
+        		if ($listener instanceof DocumentListener) {
+        			$listenerInst = $listener;
+        			break 2;
+        		}
+        	}
+        }
+        $listenerInst || die('Listener is not registered in the event manager');
+        $evm = $em->getEventManager();
+        $evm->removeEventListener(array('onFlush', 'preRemove', 'postPersist', 'postUpdate',  'postRemove'), $listenerInst);
+        
         // First step : we populate the dbpedia uris thanks to the dbpedia-owl:wikiPageID
         echo "\nFIRST STEP";
         $query = $em->createQuery('SELECT t FROM WikiTagBundle:Tag t WHERE t.wikipediaPageId IS NOT NULL ORDER BY t.label ASC');//->setMaxResults(240)->setFirstResult(500);