Massively speed up logging in by reducing the message expiring query from around 2s to 0.0002s

Author: Page-

db/patches/V1_6_47_02__optimise_message_indexes.sql

@@ -11,3 +11,8 @@ ADD INDEX game_id (
 ALTER TABLE message ADD INDEX (
 	message_type_id
 );
+
+-- This index is used on logging in, to expire out of date messages.
+ALTER TABLE message ADD INDEX (
+	expire_time
+);

htdocs/login_processing.php

@@ -236,7 +236,7 @@
 	$href = SmrSession::getNewHREF(create_container('login_check_processing.php'), true);
 	SmrSession::update();
 	//get rid of expired messages
-	$db2->query('UPDATE message SET receiver_delete = \'TRUE\', sender_delete = \'TRUE\' WHERE expire_time < '.$db->escapeNumber(TIME).' AND expire_time > 0');
+	$db2->query('UPDATE message SET receiver_delete = \'TRUE\', sender_delete = \'TRUE\', expire_time = 0 WHERE expire_time < '.$db->escapeNumber(TIME).' AND expire_time != 0');
 	// Mark message as read if it was sent to self as a mass mail.
 	$db2->query('UPDATE message SET msg_read = \'TRUE\' WHERE account_id = sender_id AND message_type_id IN (' . $db->escapeArray(array(MSG_ALLIANCE, MSG_GLOBAL, MSG_POLITICAL)) . ');');
 	//check to see if we need to remove player_has_unread