Index: biblio_handler_field_contributor.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/biblio/views/biblio_handler_field_contributor.inc,v
retrieving revision 1.1.2.1
diff -u -p -r1.1.2.1 biblio_handler_field_contributor.inc
--- biblio_handler_field_contributor.inc	3 Jun 2009 19:39:41 -0000	1.1.2.1
+++ biblio_handler_field_contributor.inc	15 Jun 2009 14:43:02 -0000
@@ -40,14 +40,24 @@ class biblio_handler_field_contributor e
     $this->items = array();
 
     foreach ($values as $result) {
-      $vids[] = $result->{$this->aliases['vid']};
+      // Don't add empty results to the array.
+      if ($result->{$this->aliases['vid']} != '') {
+        $vids[] = $result->{$this->aliases['vid']};
+      }
     }
 
     if (count($vids)) {
+      // Optimize query if $vids has only 1 item in the array, to use '=' instead of 'IN'.
+      if (count($vids) > 1){
+        $vidstr = 'vid IN ('. implode(',', $vids) .')';
+      }
+      else {
+        $vidstr = 'vid = '. $vids[0];
+      }
       $result = db_query('SELECT * FROM {biblio_contributor} bc
                           INNER JOIN {biblio_contributor_data} bcd ON bc.cid = bcd.cid
-													WHERE vid IN ('. implode(',', $vids) .')'.
-                         ' AND auth_category='.$this->auth_category.
+													WHERE '. $vidstr .
+                         ' AND auth_category='. $this->auth_category.
                          ' ORDER BY bc.rank');
       while ($item = db_fetch_array($result)) {
         // Clean up the $item from vid.