From 04c0b4f99df7c303f93d5f6c0aac15df64aa6dfa Mon Sep 17 00:00:00 2001
From: Ryan Boren <ryan@git.wordpress.org>
Date: Tue, 7 Nov 2006 23:43:59 +0000
Subject: [PATCH] GROUP BY is hella faster than DISTINCT.

git-svn-id: https://develop.svn.wordpress.org/trunk@4450 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-includes/query.php | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/wp-includes/query.php b/wp-includes/query.php
index fb13aa519d..fa8e704e48 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -583,6 +583,7 @@ class WP_Query {
 		$limits = '';
 		$join = '';
 		$search = '';
+		$groupby = '';
 
 		if ( !isset($q['post_type']) )
 			$q['post_type'] = 'post';
@@ -801,12 +802,10 @@ class WP_Query {
 					$out_cats = " AND ID NOT IN ($out_posts)";
 			}
 			$whichcat = $in_cats . $out_cats;
-			$distinct = 'DISTINCT';
+			$groupby = "{$wpdb->posts}.ID";
 		}
 
 		// Category stuff for nice URLs
-
-		global $cache_categories;
 		if ('' != $q['category_name']) {
 			$reqcat = get_category_by_path($q['category_name']);
 			$q['category_name'] = str_replace('%2F', '/', urlencode(urldecode($q['category_name'])));
@@ -836,7 +835,7 @@ class WP_Query {
 			$whichcat .= get_category_children($q['cat'], '', ', ');
 			$whichcat = substr($whichcat, 0, -2);
 			$whichcat .= ")";
-			$distinct = 'DISTINCT';
+			$groupby = "{$wpdb->posts}.ID";
 		}
 
 		// Author/user stuff
@@ -975,7 +974,6 @@ class WP_Query {
 		// Apply post-paging filters on where and join.  Only plugins that
 		// manipulate paging queries should use these hooks.
 		$where = apply_filters('posts_where_paged', $where);
-		$groupby = '';
 		$groupby = apply_filters('posts_groupby', $groupby);
 		if ( ! empty($groupby) )
 			$groupby = 'GROUP BY ' . $groupby;