Index: lib/class.tx_dam_db.php
===================================================================
--- lib/class.tx_dam_db.php	(revision 42490)
+++ lib/class.tx_dam_db.php	(working copy)
@@ -1104,6 +1104,8 @@
 		if ($uploadsPath) {
 			$where[] = 'tx_dam_file_tracking.file_path='.$GLOBALS['TYPO3_DB']->fullQuoteStr($uploadsPath,'tx_dam_file_tracking');
 		}
+			// use index to preselect records
+		$where[] = $softRef_table . '.ref_string = CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 		$where[] = $softRef_table . '.ref_string LIKE CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 		$selectFields = implode(',', $fields);
 		$whereClause = implode(' AND ', $where);
Index: lib/class.tx_dam_iterator_references.php
===================================================================
--- lib/class.tx_dam_iterator_references.php	(revision 42490)
+++ lib/class.tx_dam_iterator_references.php	(working copy)
@@ -367,6 +367,8 @@
 				// Look for references in file tracking table
 			$where = array($softRefWhere);
 			$where[] = $tracking_table . '.file_hash=' . $local_table . '.file_hash';
+				// use index to preselect records
+			$where[] = $softRef_table . '.ref_string = CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 			$where[] = $softRef_table . '.ref_string LIKE CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 			$whereClause = implode(' AND ', $where);
 			$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery(
@@ -412,6 +414,8 @@
 			$fields = $local_table . '.uid';
 			$where = array($softRefWhere);
 			$where[] = $tracking_table . '.file_hash=' . $local_table . '.file_hash';
+				// use index to preselect records
+			$where[] = $softRef_table . '.ref_string = CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 			$where[] = $softRef_table . '.ref_string LIKE CONCAT(' . $tracking_table . '.file_path,' . $tracking_table . '.file_name)';
 			$whereClause = implode(' AND ', $where);
 			$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery(