Fetch user_id before doing logging table scan, this helps a lot.

Remove FORCE INDEX, STRAIGHT JOIN, refactor query building a bit.

diff --git a/includes/SpecialLog.php b/includes/SpecialLog.php
index 5281898..c8b9a13 100644 (file)
--- a/includes/SpecialLog.php
+++ b/includes/SpecialLog.php
@@ -61,8 +61,10 @@ class LogReader {
        function setupQuery( $request ) {
                $page = $this->db->tableName( 'page' );
                $user = $this->db->tableName( 'user' );
-               $this->joinClauses = array( "LEFT OUTER JOIN $page ON log_namespace=page_namespace AND log_title=page_title" );
-               $this->whereClauses = array( 'user_id=log_user' );
+               $this->joinClauses = array( 
+                       "LEFT OUTER JOIN $page ON log_namespace=page_namespace AND log_title=page_title",
+                       "INNER JOIN $user ON user_id=log_user" );
+               $this->whereClauses = array();
 
                $this->limitType( $request->getVal( 'type' ) );
                $this->limitUser( $request->getText( 'user' ) );
@@ -95,13 +97,19 @@ class LogReader {
        function limitUser( $name ) {
                if ( $name == '' )
                        return false;
-               $title = Title::makeTitle( NS_USER, $name );
-               if ( is_null( $title ) )
+               $usertitle = Title::makeTitle( NS_USER, $name );
+               if ( is_null( $usertitle ) )
                        return false;
-               $this->user = $title->getText();
-               $safename = $this->db->strencode( $this->user );
-               $user = $this->db->tableName( 'user' );
-               $this->whereClauses[] = "user_name='$safename'";
+               $this->user = $usertitle->getText();
+               
+               /* Fetch userid at first, if known, provides awesome query plan afterwards */
+               $userid = $this->db->selectField('user','user_id',array('user_name'=>$this->user));
+               if (!$userid)
+                       /* It should be nicer to abort query at all, 
+                          but for now it won't pass anywhere behind the optimizer */
+                       $this->whereClauses[] = "NULL";
+               else
+                       $this->whereClauses[] = "log_user=$userid";
        }
 
        /**
@@ -147,12 +155,9 @@ class LogReader {
                $sql = "SELECT log_type, log_action, log_timestamp,
                        log_user, user_name,
                        log_namespace, log_title, page_id,
-                       log_comment, log_params FROM $user, $logging ";
-               if ($this->type=="" && $this->db->indexExists('logging','times')) {
-                       $sql .= ' /*! FORCE INDEX (times) */ ';
-               }
+                       log_comment, log_params FROM $logging ";
                if( !empty( $this->joinClauses ) ) {
-                       $sql .= implode( ',', $this->joinClauses );
+                       $sql .= implode( ' ', $this->joinClauses );
                }
                if( !empty( $this->whereClauses ) ) {
                        $sql .= " WHERE " . implode( ' AND ', $this->whereClauses );