Anomie has uploaded a new change for review.
https://gerrit.wikimedia.org/r/236190
Change subject: ApiQueryDeletedRevisions: Optimize ascenting title generation
......................................................................
ApiQueryDeletedRevisions: Optimize ascenting title generation
When generating titles rather than revids, it would be nice if we could
query with DISTINCT to get the titles directly instead of processing
every deleted revision for the title.
Sadly, it turns out this only works with dir=newer (dir=older is the
default). But that's probably better than nothing.
Bug: T110792
Change-Id: Idd300510c92b00722574d046399dbeb486afa98b
---
M includes/api/ApiQueryAllDeletedRevisions.php
1 file changed, 39 insertions(+), 5 deletions(-)
git pull ssh://gerrit.wikimedia.org:29418/mediawiki/core
refs/changes/90/236190/1
diff --git a/includes/api/ApiQueryAllDeletedRevisions.php
b/includes/api/ApiQueryAllDeletedRevisions.php
index 4e4d2af..f802c95 100644
--- a/includes/api/ApiQueryAllDeletedRevisions.php
+++ b/includes/api/ApiQueryAllDeletedRevisions.php
@@ -83,6 +83,21 @@
}
}
+ // If we're generating titles only, we can use DISTINCT for a
better
+ // query. But we can't do that in 'user' mode (wrong index),
and we can
+ // only do it when sorting ASC (because MySQL apparently can't
use an
+ // index backwards for grouping even though it can for ORDER
BY, WTF?)
+ $dir = $params['dir'];
+ $optimizeGenerateTitles = false;
+ if ( $mode === 'all' && $params['generatetitles'] &&
$resultPageSet !== null ) {
+ if ( $dir === 'newer' ) {
+ $optimizeGenerateTitles = true;
+ } else {
+ $p = $this->getModulePrefix();
+ $this->setWarning( "For better performance when
generating titles, set {$p}dir=newer" );
+ }
+ }
+
$this->addTables( 'archive' );
if ( $resultPageSet === null ) {
$this->parseParameters( $params );
@@ -90,7 +105,12 @@
$this->addFields( array( 'ar_title', 'ar_namespace' ) );
} else {
$this->limit = $this->getParameter( 'limit' ) ?: 10;
- $this->addFields( array( 'ar_title', 'ar_namespace',
'ar_timestamp', 'ar_rev_id', 'ar_id' ) );
+ $this->addFields( array( 'ar_title', 'ar_namespace' ) );
+ if ( $optimizeGenerateTitles ) {
+ $this->addOption( 'DISTINCT' );
+ } else {
+ $this->addFields( array( 'ar_timestamp',
'ar_rev_id', 'ar_id' ) );
+ }
}
if ( $this->fld_tags ) {
@@ -130,7 +150,6 @@
}
}
- $dir = $params['dir'];
$miser_ns = null;
if ( $mode == 'all' ) {
@@ -229,7 +248,14 @@
if ( !is_null( $params['continue'] ) ) {
$cont = explode( '|', $params['continue'] );
$op = ( $dir == 'newer' ? '>' : '<' );
- if ( $mode == 'all' ) {
+ if ( $optimizeGenerateTitles ) {
+ $this->dieContinueUsageIf( count( $cont ) != 2
);
+ $ns = intval( $cont[0] );
+ $this->dieContinueUsageIf( strval( $ns ) !==
$cont[0] );
+ $title = $db->addQuotes( $cont[1] );
+ $this->addWhere( "ar_namespace $op $ns OR " .
+ "(ar_namespace = $ns AND ar_title $op=
$title)" );
+ } elseif ( $mode == 'all' ) {
$this->dieContinueUsageIf( count( $cont ) != 4
);
$ns = intval( $cont[0] );
$this->dieContinueUsageIf( strval( $ns ) !==
$cont[0] );
@@ -259,7 +285,13 @@
$sort = ( $dir == 'newer' ? '' : ' DESC' );
$orderby = array();
- if ( $mode == 'all' ) {
+ if ( $optimizeGenerateTitles ) {
+ // Targeting index name_title_timestamp
+ if ( $params['namespace'] === null || count(
array_unique( $params['namespace'] ) ) > 1 ) {
+ $orderby[] = "ar_namespace $sort";
+ }
+ $orderby[] = "ar_title $sort";
+ } elseif ( $mode == 'all' ) {
// Targeting index name_title_timestamp
if ( $params['namespace'] === null || count(
array_unique( $params['namespace'] ) ) > 1 ) {
$orderby[] = "ar_namespace $sort";
@@ -283,7 +315,9 @@
foreach ( $res as $row ) {
if ( ++$count > $this->limit ) {
// We've had enough
- if ( $mode == 'all' ) {
+ if ( $optimizeGenerateTitles ) {
+ $this->setContinueEnumParameter(
'continue', "$row->ar_namespace|$row->ar_title" );
+ } elseif ( $mode == 'all' ) {
$this->setContinueEnumParameter(
'continue',
"$row->ar_namespace|$row->ar_title|$row->ar_timestamp|$row->ar_id"
);
--
To view, visit https://gerrit.wikimedia.org/r/236190
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: Idd300510c92b00722574d046399dbeb486afa98b
Gerrit-PatchSet: 1
Gerrit-Project: mediawiki/core
Gerrit-Branch: master
Gerrit-Owner: Anomie <[email protected]>
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