From: Roan Kattouw <roan.kattouw@gmail.com>
Date: Wed, 3 May 2017 15:00:08 +0000 (-0700)
Subject: Use IGNORE INDEX(ls_log_id) instead of FORCE INDEX(ls_field_val)
X-Git-Tag: 1.31.0-rc.0~3352^2
X-Git-Url: http://git.cyclocoop.org/%22%20.%20generer_url_ecrire%28%22articles%22%2C%22id_article=%24id_article%22%29%20.%20%22?a=commitdiff_plain;h=a70ef33e005080c2e41fa18bd5d3b99e8313bebd;p=lhc%2Fweb%2Fwiklou.git

Use IGNORE INDEX(ls_log_id) instead of FORCE INDEX(ls_field_val)

ls_field_val was renamed to PRIMARY, but this is only partially
complete in WMF production. There is only one other index on the
log_search table, so ignoring that one is equivalent to forcing
the other one.

Bug: T17441
Change-Id: I63182a9f94eabb4cc47414d86b02c82bde1e58b0
---

diff --git a/includes/logging/LogPager.php b/includes/logging/LogPager.php
index ea28ff202e..e02b8a6618 100644
--- a/includes/logging/LogPager.php
+++ b/includes/logging/LogPager.php
@@ -305,14 +305,13 @@ class LogPager extends ReverseChronologicalPager {
 		$options = $basic['options'];
 		$joins = $basic['join_conds'];
 
-		$index = [];
 		# Add log_search table if there are conditions on it.
 		# This filters the results to only include log rows that have
 		# log_search records with the specified ls_field and ls_value values.
 		if ( array_key_exists( 'ls_field', $this->mConds ) ) {
 			$tables[] = 'log_search';
-			$index['log_search'] = 'ls_field_val';
-			$index['logging'] = 'PRIMARY';
+			$options['IGNORE INDEX'] = [ 'log_search' => 'ls_log_id' ];
+			$options['USE INDEX'] = [ 'logging' => 'PRIMARY' ];
 			if ( !$this->hasEqualsClause( 'ls_field' )
 				|| !$this->hasEqualsClause( 'ls_value' )
 			) {
@@ -322,9 +321,6 @@ class LogPager extends ReverseChronologicalPager {
 				$options[] = 'DISTINCT';
 			}
 		}
-		if ( count( $index ) ) {
-			$options['USE INDEX'] = $index;
-		}
 		# Don't show duplicate rows when using log_search
 		$joins['log_search'] = [ 'INNER JOIN', 'ls_log_id=log_id' ];