From: Brad Jorsch <bjorsch@wikimedia.org>
Date: Fri, 20 Sep 2019 19:38:52 +0000 (-0400)
Subject: LogPager: Add IGNORE INDEX to avoid MariaDB optimizer bug
X-Git-Tag: 1.34.0-rc.0~111^2
X-Git-Url: https://git.cyclocoop.org/%7B%24admin_url%7Dcompta/comptes/x?a=commitdiff_plain;h=c0ea9c285d6502d55df20e8a663ca6191a4bfdcd;p=lhc%2Fweb%2Fwiklou.git

LogPager: Add IGNORE INDEX to avoid MariaDB optimizer bug

This is basically the same thing we fixed for ApiQueryLogEvents in
I16dba2158.

Bug: T223151
Change-Id: I53a7ed59de3eed2b0b4f1b1fb7f6d302b1de276c
---

diff --git a/includes/logging/LogPager.php b/includes/logging/LogPager.php
index 781df06f49..0b78a36033 100644
--- a/includes/logging/LogPager.php
+++ b/includes/logging/LogPager.php
@@ -361,6 +361,11 @@ class LogPager extends ReverseChronologicalPager {
 		if ( !$this->mTagFilter && !array_key_exists( 'ls_field', $this->mConds ) ) {
 			$options[] = 'STRAIGHT_JOIN';
 		}
+		if ( $this->performer !== '' ) {
+			// T223151: MariaDB's optimizer, at least 10.1, likes to choose a wildly bad plan for
+			// some reason for this code path. Tell it not to use the wrong index it wants to pick.
+			$options['IGNORE INDEX'] = [ 'logging' => [ 'times' ] ];
+		}
 
 		$info = [
 			'tables' => $tables,