From: Tim Starling <tstarling@users.mediawiki.org>
Date: Fri, 21 Apr 2006 03:35:01 +0000 (+0000)
Subject: Removed extra GROUP BY terms introduced in revision 13603, pending review, following... 
X-Git-Tag: 1.31.0-rc.0~57412
X-Git-Url: https://git.cyclocoop.org/%7B%24admin_url%7Dmembres/modifier.php?a=commitdiff_plain;h=3afcc87e404286c13f182c435f5a188df63014ff;p=lhc%2Fweb%2Fwiklou.git

Removed extra GROUP BY terms introduced in revision 13603, pending review, following a total DoS of enwiki due to the slow Special:Listusers query. Changing from "GROUP BY user_name" to "GROUP BY user_name,user_id" increaed the time for a LIMIT 50,50 query from 0.01 seconds to 33 seconds.
---

diff --git a/includes/SpecialListusers.php b/includes/SpecialListusers.php
index 3bf16e5b90..17cc923ee1 100644
--- a/includes/SpecialListusers.php
+++ b/includes/SpecialListusers.php
@@ -135,7 +135,7 @@ class ListUsersPage extends QueryPage {
 			"FROM $user ".
 			"LEFT JOIN $user_groups ON user_id=ug_user " .
 			$this->userQueryWhere( $dbr ) .
-			" GROUP BY user_name, user_id";
+			" GROUP BY user_name";
 
 		return $sql;
 	}
diff --git a/includes/SpecialMostcategories.php b/includes/SpecialMostcategories.php
index 0deaac9da6..17dbb5d60a 100644
--- a/includes/SpecialMostcategories.php
+++ b/includes/SpecialMostcategories.php
@@ -34,7 +34,7 @@ class MostcategoriesPage extends QueryPage {
 			FROM $categorylinks
 			LEFT JOIN $page ON cl_from = page_id
 			WHERE page_namespace = " . NS_MAIN . "
-			GROUP BY cl_from, page_namespace, page_title
+			GROUP BY cl_from
 			HAVING COUNT(*) > 1
 			";
 	}
diff --git a/includes/SpecialMostlinked.php b/includes/SpecialMostlinked.php
index 57471742d9..6b518606bb 100644
--- a/includes/SpecialMostlinked.php
+++ b/includes/SpecialMostlinked.php
@@ -37,7 +37,7 @@ class MostlinkedPage extends QueryPage {
 				page_namespace
 			FROM $pagelinks
 			LEFT JOIN $page ON pl_namespace=page_namespace AND pl_title=page_title
-			GROUP BY pl_namespace,pl_title,page_namespace
+			GROUP BY pl_namespace,pl_title
 			HAVING COUNT(*) > 1";
 	}
 
diff --git a/includes/SpecialMostrevisions.php b/includes/SpecialMostrevisions.php
index 46c66ec47a..6bc807e4cf 100644
--- a/includes/SpecialMostrevisions.php
+++ b/includes/SpecialMostrevisions.php
@@ -36,7 +36,7 @@ class MostrevisionsPage extends QueryPage {
 			FROM $revision
 			LEFT JOIN $page ON page_id = rev_page
 			WHERE page_namespace = " . NS_MAIN . "
-			GROUP BY rev_page, page_namespace, page_title
+			GROUP BY rev_page
 			HAVING COUNT(*) > 1
 			";
 	}