diff --git a/wp-includes/post.php b/wp-includes/post.php
index a0f46ad3b..2926eca86 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -3982,8 +3982,9 @@ function clean_page_cache($id) {
  * @uses update_postmeta_cache()
  *
  * @param array $posts Array of Post objects
+ * @param string $post_type The post type of the posts in $posts
  */
-function update_post_caches(&$posts) {
+function update_post_caches(&$posts, $post_type = 'post') {
 	// No point in doing all this work if we didn't match any posts.
 	if ( !$posts )
 		return;
@@ -3991,11 +3992,14 @@ function update_post_caches(&$posts) {
 	update_post_cache($posts);
 
 	$post_ids = array();
+	foreach ( $posts as $post )
+		$post_ids[] = $post->ID;
 
-	for ($i = 0; $i < count($posts); $i++)
-		$post_ids[] = $posts[$i]->ID;
+	if ( empty($post_type) )
+		$post_type = 'post';
 
-	update_object_term_cache($post_ids, 'post');
+	if ( !is_array($post_type) && 'any' != $post_type )
+		update_object_term_cache($post_ids, $post_type);
 
 	update_postmeta_cache($post_ids);
 }
diff --git a/wp-includes/query.php b/wp-includes/query.php
index 69f19b296..e5e06100e 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -1626,6 +1626,9 @@ class WP_Query {
 		if ( !isset($q['suppress_filters']) )
 			$q['suppress_filters'] = false;
 
+		if ( !isset($q['cache_results']) )
+			$q['cache_results'] = true;
+
 		if ( !isset($q['post_type']) ) {
 			if ( $this->is_search )
 				$q['post_type'] = 'any';
@@ -2504,7 +2507,8 @@ class WP_Query {
 			$this->posts[$i] = sanitize_post($this->posts[$i], 'raw');
 		}
 
-		update_post_caches($this->posts);
+		if ( $q['cache_results'] )
+			update_post_caches($this->posts, $post_type);
 
 		if ($this->post_count > 0) {
 			$this->post = $this->posts[0];