Redo WhatLinksHere query and add a *_from_namespace field to link tables

* Also tweaked the query so MySQL avoids doing a page_name
  index scan when it should start with the link table index
* Added population script (triggered by update.php)
* Also removed uniqueness from some indexes where it is redundant
* Renamed two confusing variables

Bug: 60618
Change-Id: Icca99b6ae0ef76cb77695faf82c615516191da36

17 files changed, 224 insertions, 55 deletions

diff --git a/RELEASE-NOTES-1.24 b/RELEASE-NOTES-1.24
index 4b6e74a0a595..ead5196aec0d 100644
--- a/RELEASE-NOTES-1.24
+++ b/RELEASE-NOTES-1.24
@@ -263,6 +263,9 @@ changes to languages because of Bugzilla reports.
 * Removed global function xmlsafe() from Export.php. (moved to OAIRepo extension)
 * Removed Title::userCanRead(). (deprecated since 1.19)
 * Removed maintenance script importTextFile.php. Use edit.php script instead.
+* A _from_namespace field has been added to the templatelinks, pagelinks,
+  and filelinks tables. Run update.php to apply this change to the schema.
+
 
 ==== Renamed classes ====
 * CLDRPluralRuleConverter_Expression to CLDRPluralRuleConverterExpression
diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index c353812c03c9..046a0df8bc4c 100644
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -1149,6 +1149,7 @@ $wgAutoloadLocalClasses = array(
 	'FixExtLinksProtocolRelative' => 'maintenance/fixExtLinksProtocolRelative.php',
 	'LoggedUpdateMaintenance' => 'maintenance/Maintenance.php',
 	'Maintenance' => 'maintenance/Maintenance.php',
+	'PopulateBacklinkNamespace' => 'maintenance/populateBacklinkNamespace.php',
 	'PopulateCategory' => 'maintenance/populateCategory.php',
 	'PopulateImageSha1' => 'maintenance/populateImageSha1.php',
 	'PopulateFilearchiveSha1' => 'maintenance/populateFilearchiveSha1.php',
diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 0e1f944efe8e..4606e9e6d049 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -7125,6 +7125,14 @@ $wgHKDFAlgorithm = 'sha256';
 $wgPageLanguageUseDB = false;
 
 /**
+ * Enable use of the *_namespace fields of the pagelinks, redirect, and templatelinks tables.
+ * Set this only if the fields are fully populated. This may be removed in 1.25.
+ * @var bool
+ * @since 1.24
+ */
+$wgUseLinkNamespaceDBFields = false;
+
+/**
  * For really cool vim folding this needs to be at the end:
  * vim: foldmarker=@{,@} foldmethod=marker
  * @}
diff --git a/includes/Title.php b/includes/Title.php
index 4adf2e4b6755..b7c0a255a27a 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -3814,13 +3814,31 @@ class Title {
 			$log->addRelations( 'pr_id', $logRelationsValues, $logId );
 		}
 
+		// Update *_from_namespace fields as needed
+		if ( $this->getNamespace() != $nt->getNamespace() ) {
+			$dbw->update( 'pagelinks',
+				array( 'pl_from_namespace' => $nt->getNamespace() ),
+				array( 'pl_from' => $pageid ),
+				__METHOD__
+			);
+			$dbw->update( 'templatelinks',
+				array( 'tl_from_namespace' => $nt->getNamespace() ),
+				array( 'tl_from' => $pageid ),
+				__METHOD__
+			);
+			$dbw->update( 'imagelinks',
+				array( 'il_from_namespace' => $nt->getNamespace() ),
+				array( 'il_from' => $pageid ),
+				__METHOD__
+			);
+		}
+
 		# Update watchlists
-		$oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
-		$newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
 		$oldtitle = $this->getDBkey();
 		$newtitle = $nt->getDBkey();
-
-		if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
+		$oldsnamespace = MWNamespace::getSubject( $this->getNamespace() );
+		$newsnamespace = MWNamespace::getSubject( $nt->getNamespace() );
+		if ( $oldsnamespace != $newsnamespace || $oldtitle != $newtitle ) {
 			WatchedItem::duplicateEntries( $this, $nt );
 		}
 
diff --git a/includes/deferred/LinksUpdate.php b/includes/deferred/LinksUpdate.php
index 0789b216ebe9..2c984f744385 100644
--- a/includes/deferred/LinksUpdate.php
+++ b/includes/deferred/LinksUpdate.php
@@ -358,6 +358,7 @@ class LinksUpdate extends SqlDataUpdate {
 			foreach ( $diffs as $dbk => $id ) {
 				$arr[] = array(
 					'pl_from' => $this->mId,
+					'pl_from_namespace' => $this->mTitle->getNamespace(),
 					'pl_namespace' => $ns,
 					'pl_title' => $dbk
 				);
@@ -379,6 +380,7 @@ class LinksUpdate extends SqlDataUpdate {
 			foreach ( $diffs as $dbk => $id ) {
 				$arr[] = array(
 					'tl_from' => $this->mId,
+					'tl_from_namespace' => $this->mTitle->getNamespace(),
 					'tl_namespace' => $ns,
 					'tl_title' => $dbk
 				);
@@ -400,6 +402,7 @@ class LinksUpdate extends SqlDataUpdate {
 		foreach ( $diffs as $iname => $dummy ) {
 			$arr[] = array(
 				'il_from' => $this->mId,
+				'il_from_namespace' => $this->mTitle->getNamespace(),
 				'il_to' => $iname
 			);
 		}
diff --git a/includes/installer/DatabaseUpdater.php b/includes/installer/DatabaseUpdater.php
index 28dac46314e6..b25ea09c2439 100644
--- a/includes/installer/DatabaseUpdater.php
+++ b/includes/installer/DatabaseUpdater.php
@@ -72,6 +72,7 @@ abstract class DatabaseUpdater {
 		'PopulateImageSha1',
 		'FixExtLinksProtocolRelative',
 		'PopulateFilearchiveSha1',
+		'PopulateBacklinkNamespace'
 	);
 
 	/**
diff --git a/includes/installer/MysqlUpdater.php b/includes/installer/MysqlUpdater.php
index 853ee0b770cd..dcf37b68a306 100644
--- a/includes/installer/MysqlUpdater.php
+++ b/includes/installer/MysqlUpdater.php
@@ -256,6 +256,9 @@ class MysqlUpdater extends DatabaseUpdater {
 			array( 'dropField', 'recentchanges', 'rc_cur_time', 'patch-drop-rc_cur_time.sql' ),
 			array( 'addIndex', 'watchlist', 'wl_user_notificationtimestamp', 'patch-watchlist-user-notificationtimestamp-index.sql' ),
 			array( 'addField', 'page', 'page_lang', 'patch-page_lang.sql' ),
+			array( 'addField', 'pagelinks', 'pl_from_namespace', 'patch-pl_from_namespace.sql' ),
+			array( 'addField', 'templatelinks', 'tl_from_namespace', 'patch-tl_from_namespace.sql' ),
+			array( 'addField', 'imagelinks', 'il_from_namespace', 'patch-il_from_namespace.sql' ),
 		);
 	}
 
diff --git a/includes/installer/PostgresUpdater.php b/includes/installer/PostgresUpdater.php
index 390b74f3d415..9e8ee94f0575 100644
--- a/includes/installer/PostgresUpdater.php
+++ b/includes/installer/PostgresUpdater.php
@@ -415,6 +415,9 @@ class PostgresUpdater extends DatabaseUpdater {
 			array( 'addPgIndex', 'page_props', 'pp_propname_sortkey_page',
 					'( pp_propname, pp_sortkey, pp_page ) WHERE ( pp_sortkey IS NOT NULL )' ),
 			array( 'addPgField', 'page', 'page_lang', 'TEXT default NULL' ),
+			array( 'addPgField', 'pagelinks', 'pl_from_namespace', 'INTEGER NOT NULL DEFAULT 0' ),
+			array( 'addPgField', 'templatelinks', 'tl_from_namespace', 'INTEGER NOT NULL DEFAULT 0' ),
+			array( 'addPgField', 'imagelinks', 'il_from_namespace', 'INTEGER NOT NULL DEFAULT 0' ),
 		);
 	}
 
diff --git a/includes/installer/SqliteUpdater.php b/includes/installer/SqliteUpdater.php
index cf3f06574492..ab5ab7d79e7f 100644
--- a/includes/installer/SqliteUpdater.php
+++ b/includes/installer/SqliteUpdater.php
@@ -134,6 +134,9 @@ class SqliteUpdater extends DatabaseUpdater {
 			array( 'dropField', 'recentchanges', 'rc_cur_time', 'patch-drop-rc_cur_time.sql' ),
 			array( 'addIndex', 'watchlist', 'wl_user_notificationtimestamp', 'patch-watchlist-user-notificationtimestamp-index.sql' ),
 			array( 'addField', 'page', 'page_lang', 'patch-page-page_lang.sql' ),
+			array( 'addField', 'pagelinks', 'pl_from_namespace', 'patch-pl_from_namespace.sql' ),
+			array( 'addField', 'templatelinks', 'tl_from_namespace', 'patch-tl_from_namespace.sql' ),
+			array( 'addField', 'imagelinks', 'il_from_namespace', 'patch-il_from_namespace.sql' ),
 		);
 	}
 
diff --git a/includes/specials/SpecialMergeHistory.php b/includes/specials/SpecialMergeHistory.php
index eea13363bd39..c9d3a667618b 100644
--- a/includes/specials/SpecialMergeHistory.php
+++ b/includes/specials/SpecialMergeHistory.php
@@ -452,6 +452,7 @@ class SpecialMergeHistory extends SpecialPage {
 				$dbw->insert( 'pagelinks',
 					array(
 						'pl_from' => $this->mDestID,
+						'pf_from_namespace' => $destTitle->getNamespace(),
 						'pl_namespace' => $destTitle->getNamespace(),
 						'pl_title' => $destTitle->getDBkey() ),
 					__METHOD__
diff --git a/includes/specials/SpecialWhatlinkshere.php b/includes/specials/SpecialWhatlinkshere.php
index d980f7995b27..694bc8374946 100644
--- a/includes/specials/SpecialWhatlinkshere.php
+++ b/includes/specials/SpecialWhatlinkshere.php
@@ -101,10 +101,10 @@ class SpecialWhatLinksHere extends IncludableSpecialPage {
 	 * @param int $back Display from this article ID at backwards scrolling (default: 0)
 	 */
 	function showIndirectLinks( $level, $target, $limit, $from = 0, $back = 0 ) {
-		global $wgMaxRedirectLinksRetrieved;
+		global $wgMaxRedirectLinksRetrieved, $wgUseLinkNamespaceDBFields;
+
 		$out = $this->getOutput();
 		$dbr = wfGetDB( DB_SLAVE );
-		$options = array();
 
 		$hidelinks = $this->opts->getValue( 'hidelinks' );
 		$hideredirs = $this->opts->getValue( 'hideredirs' );
@@ -113,77 +113,85 @@ class SpecialWhatLinksHere extends IncludableSpecialPage {
 
 		$fetchlinks = ( !$hidelinks || !$hideredirs );
 
-		// Make the query
-		$plConds = array(
-			'page_id=pl_from',
+		// Build query conds in concert for all three tables...
+		$conds['pagelinks'] = array(
 			'pl_namespace' => $target->getNamespace(),
 			'pl_title' => $target->getDBkey(),
 		);
-		if ( $hideredirs ) {
-			$plConds['rd_from'] = null;
-		} elseif ( $hidelinks ) {
-			$plConds[] = 'rd_from is NOT NULL';
-		}
-
-		$tlConds = array(
-			'page_id=tl_from',
+		$conds['templatelinks'] = array(
 			'tl_namespace' => $target->getNamespace(),
 			'tl_title' => $target->getDBkey(),
 		);
-
-		$ilConds = array(
-			'page_id=il_from',
+		$conds['imagelinks'] = array(
 			'il_to' => $target->getDBkey(),
 		);
 
 		$namespace = $this->opts->getValue( 'namespace' );
 		if ( is_int( $namespace ) ) {
-			$plConds['page_namespace'] = $namespace;
-			$tlConds['page_namespace'] = $namespace;
-			$ilConds['page_namespace'] = $namespace;
+			if ( $wgUseLinkNamespaceDBFields ) {
+				$conds['pagelinks']['pl_from_namespace'] = $namespace;
+				$conds['templatelinks']['tl_from_namespace'] = $namespace;
+				$conds['imagelinks']['il_from_namespace'] = $namespace;
+			} else {
+				$conds['pagelinks']['page_namespace'] = $namespace;
+				$conds['templatelinks']['page_namespace'] = $namespace;
+				$conds['imagelinks']['page_namespace'] = $namespace;
+			}
 		}
 
 		if ( $from ) {
-			$tlConds[] = "tl_from >= $from";
-			$plConds[] = "pl_from >= $from";
-			$ilConds[] = "il_from >= $from";
+			$conds['templatelinks'][] = "tl_from >= $from";
+			$conds['pagelinks'][] = "pl_from >= $from";
+			$conds['imagelinks'][] = "il_from >= $from";
 		}
 
-		// Read an extra row as an at-end check
-		$queryLimit = $limit + 1;
-
-		$options['LIMIT'] = $queryLimit;
-		$fields = array( 'page_id', 'page_namespace', 'page_title', 'rd_from' );
+		if ( $hideredirs ) {
+			$conds['pagelinks']['rd_from'] = null;
+		} elseif ( $hidelinks ) {
+			$conds['pagelinks'][] = 'rd_from is NOT NULL';
+		}
 
-		$joinConds = array( 'redirect' => array( 'LEFT JOIN', array(
-			'rd_from = page_id',
-			'rd_namespace' => $target->getNamespace(),
-			'rd_title' => $target->getDBkey(),
-			'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL'
-		) ) );
+		$queryFunc = function( $dbr, $table, $fromCol ) use ( $conds, $target, $limit ) {
+			global $wgUseLinkNamespaceDBFields;
+			// Read an extra row as an at-end check
+			$queryLimit = $limit + 1;
+			$on = array(
+				"rd_from = $fromCol",
+				'rd_title' => $target->getDBkey(),
+				'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL'
+			);
+			if ( $wgUseLinkNamespaceDBFields ) { // migration check
+				$on['rd_namespace'] = $target->getNamespace();
+			}
+			// Inner LIMIT is 2X in case of stale backlinks with no page
+			$subQuery = $dbr->selectSqlText(
+				array( $table, 'redirect' ),
+				array( $fromCol, 'rd_from' ),
+				$conds[$table],
+				__CLASS__ . '::showIndirectLinks',
+				array( 'ORDER BY' => $fromCol, 'LIMIT' => 2 * $queryLimit ),
+				array( 'redirect' => array( 'LEFT JOIN', $on ) )
+			);
+			return $dbr->select(
+				array( 'page', 'temp_backlink_range' => "($subQuery)" ),
+				array( 'page_id', 'page_namespace', 'page_title', 'rd_from' ),
+				array(),
+				__CLASS__ . '::showIndirectLinks',
+				array( 'ORDER BY' => 'page_id', 'LIMIT' => $queryLimit ),
+				array( 'page' => array( 'INNER JOIN', "$fromCol = page_id" ) )
+			);
+		};
 
 		if ( $fetchlinks ) {
-			$options['ORDER BY'] = 'pl_from';
-			$plRes = $dbr->select( array( 'pagelinks', 'page', 'redirect' ), $fields,
-				$plConds, __METHOD__, $options,
-				$joinConds
-			);
+			$plRes = $queryFunc( $dbr, 'pagelinks', 'pl_from' );
 		}
 
 		if ( !$hidetrans ) {
-			$options['ORDER BY'] = 'tl_from';
-			$tlRes = $dbr->select( array( 'templatelinks', 'page', 'redirect' ), $fields,
-				$tlConds, __METHOD__, $options,
-				$joinConds
-			);
+			$tlRes = $queryFunc( $dbr, 'templatelinks', 'tl_from' );
 		}
 
 		if ( !$hideimages ) {
-			$options['ORDER BY'] = 'il_from';
-			$ilRes = $dbr->select( array( 'imagelinks', 'page', 'redirect' ), $fields,
-				$ilConds, __METHOD__, $options,
-				$joinConds
-			);
+			$ilRes = $queryFunc( $dbr, 'imagelinks', 'il_from' );
 		}
 
 		if ( ( !$fetchlinks || !$plRes->numRows() )
diff --git a/maintenance/archives/patch-il_from_namespace.sql b/maintenance/archives/patch-il_from_namespace.sql
new file mode 100644
index 000000000000..4c858f44fcdc
--- /dev/null
+++ b/maintenance/archives/patch-il_from_namespace.sql
@@ -0,0 +1,4 @@
+ALTER TABLE /*_*/imagelinks
+  ADD COLUMN il_from_namespace int NOT NULL default 0;
+
+CREATE INDEX /*i*/il_backlinks_namespace ON /*_*/imagelinks (il_to,il_from_namespace,il_from);
\ No newline at end of file
diff --git a/maintenance/archives/patch-pl_from_namespace.sql b/maintenance/archives/patch-pl_from_namespace.sql
new file mode 100644
index 000000000000..2f7ff046dd93
--- /dev/null
+++ b/maintenance/archives/patch-pl_from_namespace.sql
@@ -0,0 +1,4 @@
+ALTER TABLE /*_*/pagelinks
+	ADD COLUMN pl_from_namespace int NOT NULL default 0;
+
+CREATE INDEX /*i*/pl_backlinks_namespace ON /*_*/pagelinks (pl_namespace,pl_title,pl_from_namespace,pl_from);
diff --git a/maintenance/archives/patch-tl_from_namespace.sql b/maintenance/archives/patch-tl_from_namespace.sql
new file mode 100644
index 000000000000..8d6c76b86640
--- /dev/null
+++ b/maintenance/archives/patch-tl_from_namespace.sql
@@ -0,0 +1,4 @@
+ALTER TABLE /*_*/templatelinks
+	ADD COLUMN tl_from_namespace int NOT NULL default 0;
+
+CREATE INDEX /*i*/tl_backlinks_namespace ON /*_*/templatelinks (tl_namespace,tl_title,tl_from_namespace,tl_from);
diff --git a/maintenance/populateBacklinkNamespace.php b/maintenance/populateBacklinkNamespace.php
new file mode 100644
index 000000000000..271a3f6fd0b5
--- /dev/null
+++ b/maintenance/populateBacklinkNamespace.php
@@ -0,0 +1,93 @@
+<?php
+/**
+ * Optional upgrade script to populate *_from_namespace fields
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Maintenance
+ */
+
+require_once __DIR__ . '/Maintenance.php';
+
+/**
+ * Maintenance script to populate *_from_namespace fields
+ *
+ * @ingroup Maintenance
+ */
+class PopulateBacklinkNamespace extends LoggedUpdateMaintenance {
+	public function __construct() {
+		parent::__construct();
+		$this->mDescription = "Populate the *_from_namespace fields";
+	}
+
+	protected function getUpdateKey() {
+		return 'populate *_from_namespace';
+	}
+
+	protected function updateSkippedMessage() {
+		return '*_from_namespace column of backlink tables already populated.';
+	}
+
+	public function doDBUpdates() {
+		$force = $this->getOption( 'force' );
+
+		$db = $this->getDB( DB_MASTER );
+
+		$this->output( "Updating *_from_namespace fields in links tables.\n" );
+
+		$start = $db->selectField( 'page', 'MIN(page_id)', false, __METHOD__ );
+		if ( !$start ) {
+			$this->output( "Nothing to do." );
+			return false;
+		}
+		$end = $db->selectField( 'page', 'MAX(page_id)', false, __METHOD__ );
+
+		# Do remaining chunk
+		$end += $this->mBatchSize - 1;
+		$blockStart = $start;
+		$blockEnd = $start + $this->mBatchSize - 1;
+		while ( $blockEnd <= $end ) {
+			$this->output( "...doing page_id from $blockStart to $blockEnd\n" );
+			$cond = "page_id BETWEEN $blockStart AND $blockEnd";
+			$res = $db->select( 'page', array( 'page_id', 'page_namespace' ), $cond, __METHOD__ );
+			foreach ( $res as $row ) {
+				$db->update( 'pagelinks',
+					array( 'pl_from_namespace' => $row->page_namespace ),
+					array( 'pl_from' => $row->page_id ),
+					__METHOD__
+				);
+				$db->update( 'templatelinks',
+					array( 'tl_from_namespace' => $row->page_namespace ),
+					array( 'tl_from' => $row->page_id ),
+					__METHOD__
+				);
+				$db->update( 'imagelinks',
+					array( 'il_from_namespace' => $row->page_namespace ),
+					array( 'il_from' => $row->page_id ),
+					__METHOD__
+				);
+			}
+			$blockStart += $this->mBatchSize - 1;
+			$blockEnd += $this->mBatchSize - 1;
+			wfWaitForSlaves();
+		}
+		return true;
+	}
+}
+
+$maintClass = "PopulateBacklinkNamespace";
+require_once RUN_MAINTENANCE_IF_MAIN;
diff --git a/maintenance/postgres/tables.sql b/maintenance/postgres/tables.sql
index cf35fe806f3c..400050e7a1f5 100644
--- a/maintenance/postgres/tables.sql
+++ b/maintenance/postgres/tables.sql
@@ -206,6 +206,7 @@ CREATE INDEX redirect_ns_title ON redirect (rd_namespace,rd_title,rd_from);
 
 CREATE TABLE pagelinks (
   pl_from       INTEGER   NOT NULL  REFERENCES page(page_id) ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
+  pl_from_namespace INTEGER NOT NULL DEFAULT 0,
   pl_namespace  SMALLINT  NOT NULL,
   pl_title      TEXT      NOT NULL
 );
@@ -214,6 +215,7 @@ CREATE INDEX pagelinks_title ON pagelinks (pl_title);
 
 CREATE TABLE templatelinks (
   tl_from       INTEGER  NOT NULL  REFERENCES page(page_id) ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
+  tl_from_namespace INTEGER NOT NULL DEFAULT 0,
   tl_namespace  SMALLINT NOT NULL,
   tl_title      TEXT     NOT NULL
 );
@@ -222,6 +224,7 @@ CREATE INDEX templatelinks_from          ON templatelinks (tl_from);
 
 CREATE TABLE imagelinks (
   il_from  INTEGER  NOT NULL  REFERENCES page(page_id) ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
+  il_from_namespace INTEGER NOT NULL DEFAULT 0,
   il_to    TEXT     NOT NULL
 );
 CREATE UNIQUE INDEX il_from ON imagelinks (il_to,il_from);
diff --git a/maintenance/tables.sql b/maintenance/tables.sql
index 6f200b251892..4b9a5e22c12e 100644
--- a/maintenance/tables.sql
+++ b/maintenance/tables.sql
@@ -473,6 +473,8 @@ CREATE INDEX /*i*/ar_revid ON /*_*/archive (ar_rev_id);
 CREATE TABLE /*_*/pagelinks (
   -- Key to the page_id of the page containing the link.
   pl_from int unsigned NOT NULL default 0,
+  -- Namespace for this page
+  pl_from_namespace int NOT NULL default 0,
 
   -- Key to page_namespace/page_title of the target page.
   -- The target page may or may not exist, and due to renames
@@ -483,7 +485,8 @@ CREATE TABLE /*_*/pagelinks (
 ) /*$wgDBTableOptions*/;
 
 CREATE UNIQUE INDEX /*i*/pl_from ON /*_*/pagelinks (pl_from,pl_namespace,pl_title);
-CREATE UNIQUE INDEX /*i*/pl_namespace ON /*_*/pagelinks (pl_namespace,pl_title,pl_from);
+CREATE INDEX /*i*/pl_namespace ON /*_*/pagelinks (pl_namespace,pl_title,pl_from);
+CREATE INDEX /*i*/pl_backlinks_namespace ON /*_*/pagelinks (pl_namespace,pl_title,pl_from_namespace,pl_from);
 
 
 --
@@ -492,6 +495,8 @@ CREATE UNIQUE INDEX /*i*/pl_namespace ON /*_*/pagelinks (pl_namespace,pl_title,p
 CREATE TABLE /*_*/templatelinks (
   -- Key to the page_id of the page containing the link.
   tl_from int unsigned NOT NULL default 0,
+  -- Namespace for this page
+  tl_from_namespace int NOT NULL default 0,
 
   -- Key to page_namespace/page_title of the target page.
   -- The target page may or may not exist, and due to renames
@@ -502,7 +507,8 @@ CREATE TABLE /*_*/templatelinks (
 ) /*$wgDBTableOptions*/;
 
 CREATE UNIQUE INDEX /*i*/tl_from ON /*_*/templatelinks (tl_from,tl_namespace,tl_title);
-CREATE UNIQUE INDEX /*i*/tl_namespace ON /*_*/templatelinks (tl_namespace,tl_title,tl_from);
+CREATE INDEX /*i*/tl_namespace ON /*_*/templatelinks (tl_namespace,tl_title,tl_from);
+CREATE INDEX /*i*/tl_backlinks_namespace ON /*_*/templatelinks (tl_namespace,tl_title,tl_from_namespace,tl_from);
 
 
 --
@@ -513,6 +519,8 @@ CREATE UNIQUE INDEX /*i*/tl_namespace ON /*_*/templatelinks (tl_namespace,tl_tit
 CREATE TABLE /*_*/imagelinks (
   -- Key to page_id of the page containing the image / media link.
   il_from int unsigned NOT NULL default 0,
+  -- Namespace for this page
+  il_from_namespace int NOT NULL default 0,
 
   -- Filename of target image.
   -- This is also the page_title of the file's description page;
@@ -521,7 +529,8 @@ CREATE TABLE /*_*/imagelinks (
 ) /*$wgDBTableOptions*/;
 
 CREATE UNIQUE INDEX /*i*/il_from ON /*_*/imagelinks (il_from,il_to);
-CREATE UNIQUE INDEX /*i*/il_to ON /*_*/imagelinks (il_to,il_from);
+CREATE INDEX /*i*/il_to ON /*_*/imagelinks (il_to,il_from);
+CREATE INDEX /*i*/il_backlinks_namespace ON /*_*/imagelinks (il_to,il_from_namespace,il_from);
 
 
 --