[ticket/11621] Add migration dropping MySQL search indexes.

Possibly time-consuming index-regeneration will be left to the user.

PHPBB3-11621

phpBB/phpbb/db/migration/data/v310/mysql_fulltext_drop.php

@@ -0,0 +1,38 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License v2
+*
+*/
+
+namespace phpbb\db\migration\data\v310;
+
+class mysql_fulltext_drop extends \phpbb\db\migration\migration
+{
+	static public function depends_on()
+	{
+		return array(
+			'\phpbb\db\migration\data\v310\dev',
+		);
+	}
+
+	public function update_schema()
+	{
+		if (strpos($this->db->sql_layer, 'mysql') === false)
+		{
+			return array();
+		}
+
+		return array(
+			'drop_keys' => array(
+				$this->table_prefix . 'posts' => array(
+					'post_subject',
+					'post_text',
+					'post_content',
+				),
+			),
+		);
+	}
+}